阅读说明：本技术 使用分离液进行样品浓缩和检测的系统和方法 (System and method for sample concentration and detection using separation fluid ) 是由 R·拉亚戈帕尔 K·J·哈尔威森 于 2014-12-16 设计创作，主要内容包括：本公开提供了使用分离液浓缩样品和检测感兴趣分析物的系统和方法。所述系统可包括样品检测容器,所述样品检测容器可包括微腔。所述微腔可包含所述样品离心所得浓缩物。所述容器还可容纳位于所述微腔和所述微腔外侧的所述样品的上清液之间的分离液。所述分离液的密度可大于所述样品的所述上清液的密度,并且所述分离液与所述上清液的界面张力可为至少0.05N/m。所述分离液可为无毒且惰性的。所述方法可包括在将所述样品检测容器离心后向所述样品检测容器添加所述分离液,以从所述微腔中置换出位于所述微腔外侧的所述上清液。(The present disclosure provides systems and methods for concentrating a sample and detecting an analyte of interest using a separation fluid. The system can include a sample detection container, which can include a microcavity. The microcavity may contain a concentrate from centrifugation of the sample. The container may also contain a separation liquid between the microcavity and the supernatant of the sample outside the microcavity. The separation liquid may have a density greater than a density of the supernatant of the sample, and an interfacial tension of the separation liquid and the supernatant may be at least 0.05N/m. The separation liquid may be non-toxic and inert. The method can include adding the separation fluid to the sample detection vessel after centrifuging the sample detection vessel to displace the supernatant fluid located outside the microcavity from the microcavity.)

1. A system for detecting an analyte of interest present in a sample, the system comprising: a sample detection container adapted to contain and concentrate a sample for detecting the presence of an analyte of interest, the container comprising:

an open end configured to receive a sample;

a closed end comprising a microcavity comprising a top opening and a base and configured to provide capillary forces to retain a sample of interest, wherein the microcavity comprises a sample concentrate resulting from centrifugation of the sample, and wherein the concentrate comprises a precipitate and at least a portion of a supernatant; and

a separation fluid located in the container between the microcavity and the supernatant, the supernatant being located outside the microcavity;

wherein the density of the separation liquid is greater than the density of the supernatant of the sample, and the interfacial tension of the separation liquid and the supernatant is at least 0.05N/m, and

wherein the separation liquid is non-toxic and inert.

2. A method for detecting an analyte of interest present in a sample, the method comprising:

providing a sample detection container comprising:

an open end configured to receive a sample, an

A closed end comprising a microcavity comprising a top opening and a base and configured to provide capillary forces to retain a sample of interest;

positioning a sample in the sample detection container;

centrifuging the sample detection container toward the microcavity to form a precipitate and a supernatant of the sample;

adding a separation fluid to the sample detection container after centrifuging the sample detection container to displace the supernatant outside the microcavity from the microcavity such that a concentrate of the sample, including the precipitate, remains in the microcavity, wherein the separation fluid moves between the microcavity and the supernatant outside the microcavity;

wherein the density of the separation liquid is greater than the density of the supernatant of the sample and the interfacial tension of the separation liquid and the supernatant is at least 0.05N/m,

wherein the separation liquid is non-toxic and inert,

wherein the analyte of interest comprises at least one of E.coli and E.coli, and

wherein the time for detecting the analyte of interest in the sample can be reduced by separating the concentrate of the sample in the microcavity by adding a separation liquid.

3. The system of claim 1 or method of claim 2, wherein the separation liquid has a density of at least 1.2 g/ml.

4. The system of claim 1 or method of claim 2, wherein the separation liquid has a density at least 0.2g/ml greater than water.

5. The system of claim 1 or the method of claim 2, wherein the surface tension of the separation liquid is no greater than 0.02N/m.

6. The system of claim 1 or method of claim 2, wherein the interfacial tension of the separation liquid and the supernatant is at least 0.055N/m.

7. The system of claim 1 or method of claim 2, wherein the sample is aqueous, and wherein the separation liquid has an interfacial tension with water of at least 0.05N/m.

8. The system of claim 1 or method of claim 2, wherein the sample is aqueous, and wherein the separation liquid has an interfacial tension with water of at least 0.055N/m.

9. The system of claim 1 or the method of claim 2, wherein the separation liquid has an aqueous solubility of less than 1%.

10. The system of claim 1 or method of claim 2, wherein the separation liquid is colorless.

11. The system of claim 1 or method of claim 2, wherein the separation liquid comprises a fluorocarbon-based liquid.

12. The system of claim 1 or method of claim 2, wherein the microcavity is a single microcavity.

13. The system of claim 1 or the method of claim 2, wherein the microcavity is one of a plurality of microcavities.

14. The system of claim 1 or method of claim 2, wherein the microcavity comprises a volume of no greater than 1 microliter.

15. The system of claim 1 or method of claim 2, wherein the microcavity has a frustoconical shape or a truncated pyramidal shape.

16. The system of claim 1 or the method of claim 2, wherein the microcavity comprises sidewalls, and wherein the sidewalls comprise a draft angle of at least 10 degrees.

17. The system of claim 1 or method of claim 2, wherein the interior surface of the container has a static water surface contact angle of at least 65 degrees.

18. The system of claim 1 or method of claim 2, wherein the interior surface of the vessel has a dynamic receding water surface contact angle of at least 25 degrees.

19. The system of claim 1 or method of claim 2, wherein the interior surface of the container has a surface roughness characterized by a roughness average (Ra) value of less than 500 nm.

20. A system for detecting an analyte of interest present in a sample, the system comprising:

a first container assembly comprising a filter portion comprising a filter having a first side and comprising a filtrate of the sample on the first side; and

a second container assembly comprising the filter portion coupled to a sample detection container of the system of claim 1, the filter portion and the sample detection container coupled together such that the first side of the filter faces the microcavity of the sample detection container.

21. The method of claim 2, wherein positioning a sample in the sample detection container comprises:

providing a first container assembly comprising a filter portion comprising a filter configured to retain an analyte of interest from the sample, the filter having a first side and comprising a filtrate of the sample on the first side; and

coupling the filter portion to the sample detection container to form a second container assembly, the filter portion and the sample detection container coupled together such that the first side of the filter faces the microcavity of the sample detection container.

22. The method of claim 2, wherein positioning a sample in the sample detection container comprises:

providing a first container assembly comprising a receiver portion adapted to contain the sample and a filter portion adapted to be removably coupled to the receiver portion, the filter portion comprising a filter configured to retain an analyte of interest from the sample, the filter having a first side;

filtering the sample by moving the sample from the receiver portion in a first direction towards the first side of the filter to form a filtrate of the sample on the first side of the filter while removing a filtrate of the sample; and

separating the receiver portion of the first container assembly from the filter portion;

coupling the filter portion to the sample detection container to form a second container assembly, the filter portion and the sample detection container coupled together such that the first side of the filter faces the microcavity of the sample detection container.

Technical Field

The present disclosure relates generally to systems and methods for detecting analytes of interest, such as bacteria in a sample, and in particular, to rapid detection of analytes of interest in relatively large sample quantities.

Background

Testing for the presence of microorganisms (e.g., bacteria, viruses, fungi, spores, etc.) and/or other analytes of interest (e.g., toxins, allergens, hormones, etc.) in water samples is critical in a variety of applications, such as food and water safety, infectious disease diagnosis, and environmental monitoring. For example, edible samples (such as food, beverages, and/or public water ingested by the general population) may contain or have microorganisms or other analytes therein that may thrive or grow with the environment in which they are located. This increase can lead to proliferation of pathogenic microorganisms, which can produce toxins or multiply to infectious doses. By way of further example, a variety of analytical methods may be performed on a non-edible sample (e.g., groundwater, urine, etc.) to determine whether the sample contains a particular analyte. For example, groundwater may be tested for microorganisms or chemical toxins; urine can be tested for a variety of diagnostic indicators to effect a diagnosis (e.g., diabetes, pregnancy, etc.).

Disclosure of Invention

Some aspects of the present disclosure provide a sample detection container adapted to contain and concentrate a sample for detecting the presence of an analyte of interest. The container may include an open end configured to receive a sample, and a closed end including a microcavity. The microcavity can include a top opening and a base, and can be configured to provide a capillary force to retain a sample of interest. The microcavity may include a sample concentrate resulting from centrifugation of the sample, which concentrate may include the precipitate and at least a portion of the supernatant. The container may further include a separation liquid located between the microcavity and a supernatant liquid located outside the microcavity. The separation liquid may have a density greater than the density of the sample supernatant and an interfacial tension with the supernatant of at least 0.05N/m. The separation liquid may be non-toxic and inert.

Some aspects of the present disclosure may provide a method for detecting an analyte of interest present in a sample. The method may include providing a sample detection container. The container may include an open end configured to receive a sample, and a closed end comprising a microcavity. The microcavity can include a top opening and a base and be configured to provide a capillary force to retain the sample of interest. The method may further comprise positioning the sample in a sample detection container; and centrifuging the sample detection container toward the microcavity to form a precipitate and a supernatant of the sample. The method can further include adding a separation fluid to the sample detection vessel after centrifuging the sample detection vessel to displace supernatant fluid from the microcavity that is outside the microcavity such that a sample concentrate, the concentrate comprising a precipitate, remains in the microcavity. The separation liquid is movable between the micro-chamber and the supernatant liquid located outside the micro-chamber. The separation liquid may have a density greater than the density of the sample supernatant and an interfacial tension with the supernatant of at least 0.05N/m. The separation liquid may be non-toxic and inert.

Other features and aspects of the present disclosure will be apparent by consideration of the detailed description and accompanying drawings.

Drawings

Fig. 1 is an exploded perspective view of a sample detection container according to one embodiment of the present disclosure.

FIG. 2 is an exploded side sectional view of the sample detection container of FIG. 1.

Fig. 3 is a close-up side sectional view of the sample detection container of fig. 1 and 2.

Fig. 3A-3C are close-up side sectional views, respectively, of a sample detection container according to another embodiment of the present disclosure.

Fig. 4 illustrates a sample detection method according to one embodiment of the present disclosure, showing a side elevation view of the sample detection container of fig. 1-3.

Fig. 5 is a close-up partial schematic cross-sectional view of a portion of the sample detection container of fig. 1-4, taken as shown in fig. 4.

Fig. 6 is an exploded perspective view of a sample detection container according to another embodiment of the present disclosure.

FIG. 7 is an exploded side sectional view of the sample detection container of FIG. 6.

Fig. 8 is a side elevation view of a sample detection container according to another embodiment of the present disclosure.

FIG. 9 is a close-up partial schematic cross-sectional view of a portion of the sample detection container of FIG. 8, taken as shown in FIG. 8.

Fig. 10 is an exploded perspective view of a first container assembly including a receiver portion and a filter portion according to one embodiment of the present disclosure.

Fig. 11 is an assembled perspective view of the first container assembly of fig. 10.

Fig. 12 is an exploded perspective view of a second container assembly including the filter portion of fig. 10-11 and the sample detection container of fig. 1-3, 4, and 5, according to one embodiment of the present disclosure.

Fig. 13 is an assembled side sectional view of the second container assembly of fig. 12.

Fig. 14 illustrates a sample detection method according to another embodiment of the present disclosure, which illustrates a side elevation view of the first container assembly of fig. 10-11 and the second container assembly of fig. 12-13.

Fig. 15A is a side sectional view of a sample detection container SMD1 used in an example where the effective angle a between the individual micro-cavities of the SMD1 and the wall is 45 degrees.

Fig. 15B is a close-up side sectional view of the microcavity of the SMD1 of fig. 15A.

Fig. 16A is a side sectional view of a sample detection container SMD2 used in an example, where the effective angle a between the individual micro-cavities of the SMD2 and the wall is 60 degrees.

Fig. 16B is a close-up side sectional view of the microcavity of the SMD2 of fig. 16A.

Fig. 17A is a side cross-sectional view of a sample detection container SMD3 used in an example where the effective angle a between the individual micro-cavities of the SMD3 and the wall is 45 degrees.

Fig. 17B is a close-up side sectional view of the microcavity of the SMD3 of fig. 17A.

Fig. 18A is a side sectional view of a sample detection container SMD4 used in an example where the effective angle a between the individual microcavity and the wall of the SMD4 is 60 degrees.

Fig. 18B is a close-up side sectional view of the microcavity of the SMD4 of fig. 18A.

Fig. 19 is a side sectional view of a sample detection vessel MS1 used in the examples, the microcavity surface of MS1 containing a plurality of microcavities.

Fig. 20A is a side cross-sectional view of a sample detection vessel MS2 used in the examples, the microcavity surface of MS2 containing a plurality of microcavities.

Fig. 20B is a close-up side sectional view of the microcavity surface of MS2 of fig. 20A.

Fig. 21A to 21D are optical micrographs of the microcavity of the SMD1 of fig. 15A and 15B.

Fig. 22A to 22D are optical micrographs of the microcavity of the SMD2 of fig. 16A and 16B.

Fig. 23A to 23D are optical micrographs of the microcavity of the SMD3 of fig. 17A and 17B.

Fig. 24A to 24D are optical micrographs of the microcavity of the SMD4 of fig. 18A and 18B.

Fig. 25A-25D are optical micrographs of the microcavity surface of MS1 of fig. 19.

Fig. 26A-26D are optical micrographs of the microcavity surface of the MS2 of fig. 20A and 20B.

Fig. 27A to 27B are optical micrographs of bacteria inside microcavities of SMD3 and SMD4 containers, respectively, in examples.

Fig. 28A-28J show side cross-sectional views of containers with different effective angles tested according to example 9.

Detailed Description

Before any embodiments of the present disclosure are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the term "coupled" and variations thereof are used broadly and encompass both direct and indirect couplings. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. Furthermore, terms such as "top," "bottom," and the like are only used to describe elements as they relate to one another, but do not necessarily recite specific orientations of the apparatus to indicate or imply necessary or desired orientations of the apparatus, or to specify how the invention described herein will be used, mounted, displayed, or positioned in use.

In various samples where an analyte of interest needs to be tested, the analyte may be present in the sample at low concentrations. For example, water safety regulations may require that the test equipment be capable of detecting 1 colony forming unit (cfu) of bacteria of interest in 100mL of water. It may be difficult or even impossible to detect such low concentrations in a reasonable time, let alone in a "fast" time, as will be described in more detail below. To shorten the detection time, in some cases, it may be necessary to concentrate the sample to a smaller volume. That is, in some cases, it may be necessary to concentrate the sample by several orders of magnitude in order to achieve a suitable concentration of the analyte of interest to achieve the detection threshold of the analytical technique in a shorter time.

In some existing systems and methods, centrifugation is used for samples in which the analyte concentration (e.g., bacterial concentration) is high enough to form visible packed "particles" at the base of the centrifuge tube. The supernatant obtained during centrifugation can then be removed by decantation or aspiration. The appropriate volume of supernatant to remove can be determined by visual inspection both in decantation and aspiration, and significant analyte loss can occur at the interface between the supernatant and the particles. In addition, for samples where the concentration of the analyte of interest is particularly low, during centrifugation, the analyte may migrate to the base of the centrifuge bottle but may not form visible particles or may not be tightly packed. In this case, the analytes may be easily separated during decantation or aspiration, which may reduce the overall collection efficiency of the analytes of interest and may reduce the accuracy of the sample testing process.

Thus, in some existing systems and methods, separate filtration may be employed to concentrate low concentration samples. While filtration can increase the concentration of an analyte of interest in a sample, the process of recovering a concentrated sample from a filter can be difficult and/or time consuming. For example, in some cases, a larger elution volume (e.g., 5-100mL) may be required to back flush or wash the concentrated sample from the filter, particularly for samples with larger initial volumes that may require larger diameter filters.

The present disclosure relates generally to systems and methods for detecting the presence or absence of an analyte of interest in a sample, particularly a liquid sample, more particularly a diluted water sample. Further, the present disclosure relates generally to systems and methods for rapid detection of analytes. In some embodiments, the analyte is selected to detect, for example, escherichia coli (escherichia coli) or other coliforms (e.g., presence or absence) in a water sample. The detection of microorganisms of interest (or other analytes) in a water sample can be difficult because of the low concentration of these microorganisms. Detection using existing systems and methods can be very slow due to the low concentration, as the microorganism needs to grow (or the analyte concentration needs to be increased) to detectable levels, a process that can take time. However, the present inventors have invented systems and methods for greatly reducing the time required to detect an analyte of interest in a water sample, particularly a diluted water sample.

The systems and methods of the present disclosure employ a sample detection container that is adapted to hold and concentrate (e.g., by centrifugation) a sample while also retaining a concentrate of the sample for detection of an analyte of interest. Such sample detection containers may include one or more microcavities at their closed ends configured to receive and retain sample concentrate (e.g., by capillary forces). Such a concentrate may comprise a sample precipitate that may form during centrifugation. The microcavity may include a top opening, a base, and a longitudinal axis. In some embodiments, the sample detection container can include a wall (or side wall or sloped wall) that extends to (e.g., tapers to) the microcavity, and a portion of the wall located adjacent to the top opening of the microcavity can have a bevel that is oriented at an effective angle α relative to the longitudinal axis of the microcavity. In some embodiments, the sample detection container can include or be configured to receive a separation liquid that is used to separate (e.g., phase separate) the concentrate contained in the microcavity from a majority of the liquid (e.g., supernatant from centrifugation) located outside of the microcavity (e.g., upper portion of the microcavity) to separate the concentrate from the remainder of the sample. Specifically, the separation liquid is configured to be located below most of the supernatant liquid and above the microcavity such that the separation liquid is configured to be located between the microcavity (and its contents) and the supernatant liquid outside the microcavity.

For simplicity, one microcavity will be described primarily; it should be understood, however, that any description of a single microcavity can also be extended to include multiple microcavities, or "microcavity surfaces".

Some methods of the present disclosure may generally include providing a sample detection container; positioning a sample to be tested in a sample detection container; centrifuging the sample detection container in a first direction toward the microcavity to form a precipitate and a supernatant of the sample; and adding a separation liquid to the sample detection container after centrifugation to displace the supernatant liquid located outside the microcavity from the microcavity and to effectively separate the sample concentrate contained in the microcavity from the supernatant liquid.

Thus, the inventors have found that the time for detecting an analyte of interest in a sample can be reduced by separating a concentrate of the sample in a microcavity using a separation liquid. Such separation of the concentrate will generally minimize the amount of analyte of interest resolved, which will maximize the resulting concentration of the analyte of interest (if present), thereby minimizing the time required to detect the analyte of interest.

Some methods of the present disclosure may further include inverting the sample detection container after centrifuging the sample detection container to decant at least a portion of the supernatant and the centrate from the microcavity such that a sample concentrate, the concentrate comprising the precipitate, remains in the microcavity. The method may further include resolving whether the concentrate in the microcavity contains the analyte of interest. The resolution can be performed in the microcavity even when the separation liquid is retained in the container above the microcavity.

As described in more detail below, and as exemplified in the examples, the inventors have found particular benefits and advantages when the density of the separation liquid is greater than the supernatant density of the sample and the liquid-liquid interfacial tension is at least 50 dynes/cm (0.05N/m). In addition, the separation fluid is generally non-toxic so as not to have a toxic or otherwise deleterious effect on the analyte of interest (e.g., bacteria, spores, enzymes, DNA, RNA, metabolites, etc.) in the sample to be tested, if present. In addition, the separation fluid is generally inert such that the separation fluid does not chemically react with the sample detection system (including the sample or any portion of the sample detection container). Furthermore, the separation liquid typically has very low solubility (e.g., less than 1%) in the supernatant and/or water of the sample.

The sample detection containers of the present disclosure may include one or more microcavities. Sample detection containers having a single microcavity as well as sample detection containers having microcavity surfaces (i.e., multiple microcavities generally constitute the interior surfaces of the sample detection container) are described, illustrated, and exemplified herein.

In some embodiments, the sample detection container may include a wall that extends down to the one or more microcavities, and in some embodiments, at least a portion of the wall of the container may taper down toward the one or more microcavities, for example, to facilitate movement of an analyte of interest in the sample into the one or more microcavities, particularly when a relatively small number of microcavities are employed. In such embodiments, the walls may taper or angle at an effective angle α.

The effective angle a may vary between about 0 degrees and 90 degrees. In some embodiments, the wall portions of particular interest when describing the effective angle α are the wall portions located adjacent to the microcavity top opening. In some embodiments, the wall portions "adjacent to the top opening of the microcavity" oriented at the effective angle α can be at least 5 times the representative dimensions of the microcavity, such that the wall portions oriented at the effective angle α are relatively large relative to the order of magnitude of the microcavity. For example, the transverse dimension (e.g., the dimension orthogonal to the longitudinal axis) of the microcavity at the top opening can be used as a representative dimension, with the wall (or wall portion) oriented at the effective angle α being at least 5 times that dimension. In some embodiments, the wall portions located adjacent to the microcavity and oriented at the effective angle α are at least 10 times, in some embodiments, at least 15 times, in some embodiments, at least 20 times, and in some embodiments, at least 50 times the representative dimensions of the microcavity.

In some cases (e.g., without the use of a separation liquid of the present disclosure), configuring the container to include walls at least partially adjacent to the microcavity and oriented at an effective angle α can maximize collection (and retention) of the analyte of interest in the microcavity, while also maximizing drainage of a majority of the supernatant from the microcavity (e.g., by inverting the container) by a precipitation (e.g., centrifugation) method (i.e., excess supernatant is not retained within the container above the microcavity (i.e., above the top opening of the microcavity or above a plane defined by the top opening of the microcavity)). In other words, in some embodiments, configuring the container to include walls oriented at an effective angle α can maximize the concentration of the analyte of interest, particularly when one or more microcavities, as described below, are employed. Additional details regarding effective angle α can be found in U.S. patent application No.61/918,977, filed on 12/20/2013, which is incorporated herein by reference in its entirety.

While other previous systems and methods may concentrate the sample and enable relatively early detection of the analyte of interest, the systems and methods of the present disclosure enable earlier detection by employing a separation liquid to effectively separate the concentrate of the sample in one or more microcavities.

Furthermore, in some prior systems, the availability of a concentrate (see, e.g., concentrate 154 in fig. 4 and 5) that is substantially contained in the microstructured or microstructured surface is dependent upon the speed at which the container is inverted in the inversion step. However, the systems and methods of the present disclosure employing a separation liquid are effective to obtain a concentrate that is substantially contained within the microcavity regardless of whether inversion is employed, and particularly regardless of the speed of inversion.

By "substantially contained" it may be generally meant that the concentrate is contained within the microcavity and no separation is visible (i.e., with the naked eye or naked eye) above the microcavity that can contain a larger volume of sample or concentrate.

Such larger volumes may be undesirable because any analyte of interest present in the larger volume may not be properly detected (e.g., during imaging or optical resolution), at least in part because the concentration of analyte (if present) in such larger volumes will be lower and/or the larger volumes may not be properly positioned for detection.

For recovery of a concentrated sample (filtrate) from a filter, in the systems and methods of the present disclosure, a sample detection vessel may be used to further concentrate the eluted filtrate sample. That is, in some embodiments, the systems and methods of the present disclosure may employ filtration and centrifugation in combination into one or more microcavities to separate and detect an analyte of interest (if present) from a sample. Thus, even if a larger volume is required for elution of the filtered filtrate, the eluted filtrate sample can be further concentrated by centrifugation into a microcavity (i.e., filtering the retained filtrate plus any diluent, such as an elution solution) to obtain a high concentration, small volume (e.g., on the order of nanoliters) aliquot of the sample for relatively faster detection of the analyte of interest.

For example, a large volume of diluted aqueous sample may be filtered by size, charge, or affinity to retain the analyte of interest (if present). The analyte can be retained on the first side of the filter and then can be oriented to face the microcavity during subsequent centrifugation. A diluent (e.g., nutrient medium, etc.) may be added to the filter and the analyte may be forced into the microcavities by centrifugation. In such embodiments, the filtrate on the filter plus any additional diluent can form a "sample," which can be precipitated (e.g., by centrifugation) into the microcavity such that a concentrate of the sample (i.e., a portion of the sample that is more concentrated than the starting sample) can be retained in the microcavity, wherein the concentrate comprises the precipitate of the sample (i.e., the higher density species), which will comprise the analyte (if present). The microcavity can then be resolved to detect the analyte, for example, by detecting the presence or absence of the analyte. The system of the present disclosure may include a container assembly configured to facilitate filtration and centrifugation, and to switch between filtration and centrifugation steps. Furthermore, the systems and methods of the present disclosure allow for the concentration of large volumes of sample to very small volumes, such as from about 1L to about 1 microliter, or even 1nL (e.g., in a microcavity).

In particular, in some embodiments, the systems and methods of the present disclosure may include performing a first concentration step that includes filtering an initial sample using a filter configured to retain one or more analytes of interest to form a filtrate on one side of the filter; optionally adding one or more diluents to the filtrate and using the filtrate and any added diluents as a new or second sample; and performing a concentration step that includes concentrating (e.g., based on density) the second sample into a microcavity (or microcavities), wherein the microcavity can be used as a separate small volume (e.g., on the order of microliters or nanoliters) "cuvette" to obtain a high concentration of the analyte of interest (if present) in the sample. Such an increase in the concentration of the analyte of interest may facilitate rapid detection of the analyte, for example, detection of the presence or absence of the analyte.

In some existing systems and methods, a portion of the sample may be irreversibly retained by the filter during filtration. The entrapment problem can be addressed by a homogeneous pore filter, however filtration through a homogeneous pore filter can be slow and the pores of a homogeneous pore filter can easily clog quickly during filtration. However, the inventors have found that certain filters can better recover analytes of interest (e.g., microorganisms, such as bacteria). For example, as described in more detail below, "multizone" filtration membranes (i.e., filters comprising a plurality of interstitial regions) are particularly useful for recovering bacteria from the filters. This is because the porosity of the filter varies with its z-dimension (i.e., depth). The inventors have found that by using such a multi-zone filter and using one side of the filter having the smallest pore size as the "first side" of the filter (i.e., the side of the filter through which the sample first passes and collects the filtrate), particular advantages in the recovery of the analyte of interest can be obtained.

However, as noted above, even without the use of such multi-zone filters, the systems and methods of the present disclosure are still more efficient than filtration-only systems and methods because the systems and methods of the present disclosure further concentrate the eluted filter sample, e.g., by centrifugation, into a microcavity (or microcavities) in addition to employing filtration to shorten the detection time for the analyte of interest.

In some embodiments, the analyte of interest may be the microorganism of interest itself, while in some embodiments, the analyte may be an indicator of a viable microorganism of interest. In some embodiments, the present disclosure can include systems and methods for determining the presence or absence of a microorganism of interest in a sample by resolving an analyte of interest representative of the microorganism in the sample.

In some embodiments, rapid detection may refer to a detection time of no more than 8 hours, in some embodiments, no more than 6 hours, in some embodiments, no more than 5 hours, in some embodiments, no more than 4 hours, and in some embodiments, no more than 3 hours. However, the detection time may depend on the type of analyte to be detected, as some microorganisms grow faster than others and will therefore reach the detectable threshold more quickly. One skilled in the art will know how to find an appropriate method (e.g., including an appropriate enzyme and enzyme substrate) for detecting an analyte (e.g., a microorganism) of interest. However, for a given analyte of interest, regardless of which method is used, or which analyte is selected, the systems and methods of the present disclosure will generally achieve results that are faster than standard culture techniques (e.g., growth-based detection on microtiter plates (e.g., 96-well plates)). That is, the systems and methods of the present disclosure can be at least 25% faster, in some embodiments at least 50% faster, in some embodiments at least 75% faster, and in some embodiments at least 90% faster than standard culture techniques (e.g., where each well holds 100 microliters of sample).

The sample to be analyzed for the analyte of interest can be obtained in a variety of ways. For example, in some embodiments, the sample to be analyzed is itself a liquid sample, e.g., a diluted liquid sample and/or a diluted aqueous sample. In some embodiments, the sample may comprise a liquid resulting from washing or rinsing the source of interest (e.g., surface, contaminant, etc.) with a diluent. In some embodiments, the sample may comprise a filtrate resulting from filtration or sedimentation of a liquid composition resulting after combining the source of interest with an appropriate diluent. That is, in a first filtration or settling step, larger insoluble materials and/or materials having a density less than or greater than the analyte of interest, such as various foods, contaminants, etc., can be removed from the liquid composition to form a sample to be analyzed using the methods of the present disclosure.

The term "source" may be used to refer to a food or non-food for which an analyte is to be tested. The source can be a solid, liquid, semi-solid, gel-like material, and combinations thereof. In some embodiments, the source may be provided by a substrate (e.g., a swab or a wipe) used, for example, to collect a sample from a surface of interest. In some embodiments, the liquid composition may comprise a substrate that may be further decomposed (e.g., during agitation or dissolution) to enhance recovery of the source and any analyte of interest. The surface of interest may comprise at least a portion of a variety of surfaces including, but not limited to, walls (including doors), floors, ceilings, drains, refrigeration systems, ducts (e.g., ventilation ducts), vents, toilet seats, handles, door handles, handrails, bedrails (e.g., hospitals), countertops, tabletops, dining surfaces (e.g., trays, dishes, etc.), work surfaces, equipment surfaces, clothing, etc., and combinations thereof. All or a portion of the source may be used to obtain a sample to be analyzed using the methods of the present disclosure. For example, a "source" may be a water supply or water moving through a conduit from which a relatively large volume of sample may be taken, forming a sample to be tested using the systems and methods of the present disclosure. Thus, a "sample" may also be derived from any of the above sources.

The term "food" is generally used to refer to solid, liquid (e.g., including, but not limited to, solutions, dispersions, emulsions, suspensions, etc., and combinations thereof) and/or semi-solid edible compositions. Examples of food include, but are not limited to, meat, poultry, eggs, fish, seafood, vegetables, fruits, prepared foods (e.g., soups, sauces, pastes), cereal products (e.g., flour, oatmeal, bread), canned foods, milk, other dairy products (e.g., cheese, yogurt, sour cream), fats, oils, desserts, condiments, spices, pasta, beverages, water, animal feed, drinking water, other suitable edible materials, and combinations thereof.

The term "non-food" is generally used to refer to a source of interest that is not within the definition of "food" or that is not generally considered edible. Examples of non-food sources may include, but are not limited to, clinical samples, cell lysates, whole blood or a portion of whole blood (e.g., serum), other bodily fluids or secretions (e.g., saliva, sweat, sebum, urine), stool, cells, tissues, organs, biopsies, plant material, wood, soil, sediments, pharmaceuticals, cosmetics, food supplements (e.g., American ginseng capsules), pharmaceuticals, pollutants, other suitable non-edible materials, and combinations thereof.

The term "contaminant" is generally used to refer to an inanimate object or substrate capable of carrying infectious organisms and/or transferring them. Contaminants can include, but are not limited to, cloths, mop heads, towels, sponges, wipes, utensils, coins, paper currency, cell phones, clothing (including shoes), door handles, feminine products, diapers, and the like, portions thereof, and combinations thereof.

The term "analyte" is generally used to refer to a substance to be detected (e.g., by laboratory or field testing). The sample may be tested for the presence, amount, and/or viability of a particular analyte. Such analytes may be present in the source (e.g., interior) or external to the source (e.g., exterior surface). Examples of analytes can include, but are not limited to, microorganisms, biomolecules, chemicals (e.g., pesticides, antibiotics), metal ions (e.g., mercury ions, heavy metal ions), metal ion-containing complexes (e.g., complexes comprising metal ions and organic ligands), enzymes, coenzymes, enzyme substrates, indicator dyes, colorants, Adenosine Triphosphate (ATP), Adenosine Diphosphate (ADP), adenylate kinase, luciferase, luciferin, and combinations thereof.

A variety of test methods can be used to identify or quantify the analyte of interest, including but not limited to microbiological assays, biochemical assays (e.g., immunoassays), or combinations thereof. In some embodiments, the analyte of interest can be detected by: a genetic method; immunization; a colorimetric method; fluorescence method; a light emitting method; by detecting enzymes released by living cells in the sample; by detecting light representative of an analyte of interest; detecting light by absorption, reflection, fluorescence, or a combination thereof; or a combination of the above. That is, in some embodiments, resolving a sample (or sample concentrate) includes optionally resolving a sample, which may include any of the above types of optical resolution, or any of the below types.

Specific examples of test methods that can be used include, but are not limited to, antigen-antibody interactions, molecular sensors (affinity binding), thermal analysis, microscopy (e.g., optical microscopy, fluorescence microscopy, immunofluorescence microscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM)), spectroscopy (e.g., mass spectrometry, Nuclear Magnetic Resonance (NMR) spectroscopy, raman spectroscopy, Infrared (IR) spectroscopy, x-ray spectroscopy, attenuated total reflectance spectroscopy, fourier transform spectroscopy, gamma ray spectroscopy, etc.), spectrophotometry (e.g., absorption, reflection, fluorescence, luminescence, colorimetric detection, etc.), electrochemical analysis, genetic techniques (e.g., Polymerase Chain Reaction (PCR), transcription-mediated amplification Techniques (TMA), hybridization protection detection (HPA), DNA or RNA molecule recognition assays, etc.), adenosine Triphosphate (ATP) detection assays, immunoassays (e.g., enzyme linked immunosorbent assays (ELISA)), cytotoxic assays, viral plaque assays, techniques for evaluating the effects of cytopathic effects, other suitable analyte testing methods, or combinations thereof.

The term "microorganism" is used generically to refer to any prokaryotic or eukaryotic microorganism, including, but not limited to, one or more bacteria (e.g., motile or vegetative, gram positive or gram negative), viruses (e.g., Norovirus (Norovirus), Norwalk virus (Norwalk virus), Rotavirus (Rotavirus), Adenovirus (adeno virus), DNA virus, RNA virus, enveloped, non-enveloped, Human Immunodeficiency Virus (HIV), Human Papilloma Virus (HPV), etc.), bacterial spores or endospores, algae, fungi (e.g., yeast, filamentous fungi, fungal spores), prions, mycoplasma, and protozoa. In some cases, the microorganisms of particular interest are those pathogenic microorganisms, and the term "pathogen" is used to refer to any pathogenic microorganism. Examples of pathogens may include, but are not limited to, members of the family Enterobacteriaceae (Enterobacteriaceae), or micrococcaceae (micrococcae), or species of the genus Staphylococcus (Staphylococcus), Streptococcus (Streptococcus), Pseudomonas (Pseudomonas), Enterococcus (Enterobacteriaceae), Salmonella (Salmonella), Legionella (Legionella), Shigella (Shigella), Yersinia (Yersinia), Enterobacteriaceae (Enterobacteriaceae), Escherichia (Escherichia), Listeria (Listeria), Campylobacter (Campylobacter), Acinetobacter (Acinetobacter) species, Vibrio (Vibrio), Clostridium (Clostridium) and Corynebacterium (Corynebacterium) species. Specific examples of pathogens may include, but are not limited to: coli, including enterohemorrhagic escherichia coli, e.g., serotype O157: H7, O129: H11; pseudomonas aeruginosa (Pseudomonas aeruginosa); bacillus cereus (bacillus cereus); bacillus anthracis (Bacillus anthracaris); salmonella enteritidis (Salmonella enteritidis); salmonella enterica (Salmonella enterica) typhimurium serotype; listeria monocytogenes (Listeria monocytogenes); clostridium botulinum (Clostridium botulinum); clostridium perfringens (clostridium perfringens); staphylococcus aureus (Staphylococcus aureus); methicillin-resistant staphylococcus aureus; campylobacter jejuni (Campylobacter jejuni); yersinia enterocolitica (yersinia enterocolitica); vibrio vulnificus (Vibrio vulgaris); clostridium difficile (Clostridium difficile); vancomycin-resistant enterococci; enterobacter sakazakii (Enterobacter [ Cronobacter ] sakazakii); and coliform bacteria. Environmental factors that may affect microbial growth may include the presence or absence of nutrients, pH, water content, redox potential, antimicrobial compounds, temperature, atmospheric gas composition, and biological structure or barrier.

The term "biomolecule" is generally used to refer to a molecule, or derivative thereof, that is present in or formed by an organism. For example, biomolecules may include, but are not limited to, at least one of amino acids, nucleic acids, polypeptides, proteins, polynucleotides, lipids, phospholipids, sugars, polysaccharides, and combinations thereof. Specific examples of biomolecules can include, but are not limited to, metabolites (e.g., staphylococcal enterotoxin), allergens (e.g., peanut allergen, egg allergen, pollen, dust mites, mold, dandruff, or proteins immobilized therein, etc.), hormones, toxins (e.g., bacillus diarrheal toxin, aflatoxin, clostridium difficile toxin, etc.), RNA (e.g., mRNA, total RNA, tRNA, etc.), DNA (e.g., plasmid DNA, plant DNA, etc.), marker proteins, antibodies, antigens, ATP, and combinations thereof.

The terms "soluble material" and "insoluble material" are generally used to refer to a material that is relatively soluble or insoluble in a given medium under particular conditions. Specifically, under a given set of conditions, a "soluble species" is a species that goes into solution and is soluble in the solvent (e.g., diluent) of the system. By "insoluble material" is meant a material that does not go into solution and does not dissolve in the solvent of the system under a given set of conditions. The source or sample taken from the source may comprise soluble and insoluble material (e.g. cell debris). The insoluble matter is sometimes referred to as particulates, precipitates, or debris, and may comprise a portion of the source material itself (i.e., from an inner or outer portion (e.g., outer surface) of the source) or other source residue or debris generated during agitation. In addition, the liquid composition comprising the source and the diluent may comprise a more dense material (i.e., a material that is denser than the diluent and other materials in the mixture) and a less dense material (i.e., a material that is less dense than the diluent and other materials in the mixture). Thus, a dilution of the sample can be selected such that the analyte of interest is denser than the dilution and can be concentrated by sedimentation (e.g., centrifugation).

The term "diluent" is generally used to refer to a liquid that is added to a source material to disperse, dissolve, suspend, emulsify, wash, and/or rinse the source. The diluent can be used to form a liquid composition from which a sample can be obtained to be analyzed using the methods of the present disclosure. In some embodiments, the diluent is a sterile liquid. In some embodiments, the diluent may comprise a variety of additives, including but not limited to surfactants, or other suitable additives that aid in dispersing, dissolving, suspending, or emulsifying the source for subsequent analyte testing; a rheological agent; antimicrobial neutralizing agents (e.g., for neutralizing preservatives or other antimicrobial agents); enrichment or growth media comprising nutrients (e.g., to promote selective growth of a desired microorganism) and/or growth inhibitors (e.g., to inhibit growth of an undesired microorganism); a pH buffering agent; an enzyme; indicator molecules (e.g., pH or oxidation/reduction indicators); a spore germinating agent; agents that neutralize disinfectants (e.g., sodium thiosulfate that neutralizes chlorine); agents for promoting bacterial resuscitation (e.g., sodium pyruvate); stabilizers (e.g., for stabilizing analytes of interest, including solutes such as sodium chloride, sucrose, etc.); or a combination thereof. In some embodiments, the diluent may comprise sterile water (e.g., sterile double distilled water (ddH)₂O)); one or more organic solvents to selectively dissolve, disperse, suspend, or emulsify the source; an aqueous organic solvent, or a combination thereof. In some embodiments, the diluent is a sterile buffered solution (e.g., Butterfield buffer, available from Edge Biological, Memphis TN, montfield, tennessee, usa). In some embodiments, the diluent is a selective or semi-selective nutrient formulation such that the diluent can be used for selective or semi-selective growth of a desired analyte (e.g., bacteria). In this embodiment, the dilution can be incubated with the source for a period of time (e.g., at a particular temperature) to facilitateSuch growth and/or development of the desired analyte.

Examples of growth media may include, but are not limited to, Tryptic Soy Broth (TSB), Buffered Peptone Water (BPW), universal pre-enrichment broth (UPB), Listeria Enrichment Broth (LEB), lactose broth, bolton broth, or other conventional, non-selective or mildly selective media known to those of ordinary skill in the art. The growth medium may comprise nutrients that support the growth of more than one desired microorganism (i.e., the analyte of interest).

Examples of growth inhibitors may include, but are not limited to, bile salts, sodium deoxycholate, sodium selenite, sodium thiosulfate, sodium nitrate, lithium chloride, potassium tellurite, sodium tetrathionate, sodium sulfacetamide, mandelic acid, cystine selenite tetrathionate, sulfadimidine, brilliant green, malachite green oxalate, crystal violet, Tergitol 4, sulfadiazine, amikacin, aztreonam, nalidixic acid, acriflavine, polymyxin B, novobiocin, alap, organic and inorganic acids, bacteriophages, rose dichlororose, chloramphenicol, chlortetracycline, sodium chloride at specific concentrations, sucrose and other solutes, and combinations thereof.

The term "agitation" and derivatives thereof is generally used to describe the process of subjecting a liquid composition to a given movement, such as mixing or blending the contents of such liquid composition. A variety of stirring methods can be used, including, but not limited to, manual shaking, mechanical shaking, ultrasonic vibration, vortex agitation, manual agitation, mechanical agitation (e.g., by a mechanical propeller, a magnetic stirrer, or another stirring aid, such as a ball bearing), manual whipping, mechanical whipping, blending, kneading, and combinations thereof.

The term "filtration" is generally used to refer to a process of separating substances by size, charge, and/or function. For example, filtration may include separating soluble materials and solvent (e.g., diluent) from insoluble materials, or filtration may include separating soluble materials, solvent, and relatively smaller insoluble materials from relatively larger insoluble materials. Thus, the liquid composition may be "pre-filtered" to obtain a sample to be analyzed using the methods of the present disclosure. A variety of filtration methods can be used, including, but not limited to, passing a liquid composition (e.g., containing a source of interest from which a sample to be concentrated can be obtained) through a filter, other suitable filtration methods, and combinations thereof.

"sedimentation" is generally used to refer to a process of separating substances by density, for example by allowing denser substances in a liquid composition (i.e., substances having a density greater than that of the other substances in the diluent and mixture) to settle or sink and/or by allowing less dense substances in a liquid composition (i.e., substances having a density less than that of the other substances in the diluent and mixture) to rise or float. Sedimentation may be by gravity or by centrifugation. The denser material may then be separated from the less dense material (and the diluent) by pumping the less dense material (i.e., unsettled material or supernatant) and the diluent from the denser material, by decanting the less dense material and the diluent, or a combination thereof. In addition to or instead of the pre-filtration step, a pre-settling step may be used to obtain a sample that is to be concentrated using the sample detection systems and methods of the present disclosure.

"Filter" is generally used to describe a device for separating soluble materials (or soluble materials and relatively smaller insoluble materials) and solvents from insoluble materials (or relatively larger insoluble materials) in a liquid composition and/or for filtering a sample during sample concentration. Examples of filters may include, but are not limited to: woven or nonwoven webs (e.g., wire mesh, cloth mesh, plastic mesh, etc.), woven or nonwoven polymer webs (e.g., comprising calenderable polymer fibers laid in a uniform or non-uniform process), surface filters, depth filters, membranes (e.g., ceramic alumina membrane filters available under the trade name ANOPORE from Whatman Inc, Florham Park, NJ, of Florham Park, n.), polycarbonate membranes (e.g., track etched polycarbonate membrane filters available under the trade name nucloport from Whatman, Inc.), polyester membranes (e.g., comprising track etched polyester, etc.), screens, glass wool, frits, filter paper, foam, etc., and combinations thereof.

In some embodiments, the filter may be configured to separate the microorganism of interest from the sample, e.g., by size, charge, and/or affinity. For example, in some embodiments, the filter can be configured to retain a microorganism of interest such that the filtrate retained on the filter comprises the microorganism of interest.

In some embodiments, the filter can be configured to retain at least 30%, in some embodiments, at least 50%, in some embodiments, at least 80%, in some embodiments, at least 85%, in some embodiments, at least 90%, in some embodiments, at least 95% of the analyte of interest (e.g., microorganism of interest) in the sample.

Other examples of suitable filters are described in the following patents: co-pending PCT publication No. wo2011/156251(Rajagopal et al), which claims priority from U.S. patent application No.61/352,229; PCT publication No. wo2011/156258(Mach et al), which claims priority from U.S. patent application No.61/352,205; PCT publication No. wo2011/152967(Zhou), which claims priority from U.S. patent application nos. 61/350,147 and 61/351,441; and PCT publication No. wo2011/153085(Zhou), which claims priority from U.S. patent application nos. 61/350,154 and 61/351,447, all of which are incorporated herein by reference in their entirety.

In some embodiments, the term "filtrate" is generally used to describe the liquid that remains after separation or removal of insoluble material (or at least relatively larger insoluble material) from a liquid composition. In some embodiments, the term "supernatant" is generally used to describe the liquid that remains after separation or removal of denser materials from a liquid composition. Such filtrate and/or supernatant may form a sample to be used in the present disclosure. In some embodiments, the filtrate and/or supernatant may be incubated for a period of time to allow growth of the microorganism of interest, and the resulting post-incubation filtrate and/or supernatant may form a sample to be used in the present disclosure. In some embodiments, a growth medium may be added to aid in the growth of the microorganism of interest.

In some embodiments, the term "filtrate" is generally used to describe the solids that remain after filtering a liquid source (e.g., water to be tested) to separate insoluble materials from soluble materials. Such filtrate may be further diluted and optionally stirred, grown (e.g., by addition of growth media), and/or incubated to form a sample to be used in the present disclosure. The filtrate may be present on one surface or side of the filter and/or may at least partially penetrate deep into the filter. Thus, in some embodiments, a diluent comprising an elution solution, a wash solution, or the like may be used to aid in the removal of the filtrate from the filter. In some embodiments, surface filters may be more preferred (e.g., as compared to depth filters) for aiding and enhancing the removal of filtrate from the filter.

In some embodiments, gravity applied to the filtrate during a subsequent centrifugation step can assist in removing the filtrate from the filter. In some cases, the retained analyte of interest (e.g., microorganism) may be eluted from the filter by: the filter is repositioned and gravity causes the retained biological organisms to be dislodged, thereby eluting from the filter. In other cases, the retained analyte can be eluted from the filter by manually shaking the filter to dislodge the retained analyte from the filter. In other cases, the retained analyte can be eluted by vortexing the filter to dislodge the retained analyte from the filter. In other cases, the analyte may be eluted from the filter by foam elution.

In some embodiments of detecting and/or quantifying an analyte of interest (e.g., a microorganism) after recovering the analyte of interest from the filter, the methods of the present disclosure can include eluting at least 50% of the retained analyte of interest from the filter, but the methods can also be performed after eluting less than 50% of the retained analyte from the filter. In some embodiments, at least 60%, in some embodiments, at least 70%, in some embodiments, at least 75%, in some embodiments, at least 80%, in some embodiments, at least 90%, and in some embodiments, at least 95% of the analyte may be retained by elution from the filter.

In some embodiments, regardless of the form of the starting sample, or how it is obtained, the sample may be stirred, cultured (e.g., by addition of growth media), and/or incubated to form a sample to be analyzed by the systems and methods of the present disclosure. In some embodiments, various reagents may be added at various stages of the process, including but not limited to addition to the initial sample, addition to the filtrate (e.g., with a diluent) or supernatant used to form the sample to be tested, coating and/or air drying in one or more microcavities (which would be used as a detection vessel for sample concentrate), or combinations thereof.

In some embodiments, the term "precipitate" is generally used to describe a "particle" or solid that is separated from the supernatant after separation or removal of a denser material from a liquid composition (e.g., by centrifugation).

The term "microcavity" and derivatives thereof is used generically to refer to a receptacle, recess, depression, or well that is configured to retain a liquid, solid, semi-solid, gel-like material, other suitable material, or a combination thereof, particularly in any orientation (e.g., by capillary forces) under normal gravitational forces.

In some embodiments, at least two possible dimensions of the "microcavity" are no greater than 1000 micrometers, in some embodiments, no greater than 500 micrometers, and in some embodiments, no greater than 200 micrometers. However, in some embodiments of the present disclosure, a "microcavity" can be any receptacle, recess, depression, or well sufficient to retain a portion of a sample (e.g., a liquid concentrate of the sample after centrifugation toward the microcavity) in any orientation under normal gravitational forces. Thus, the microcavities of the present disclosure can have a sufficient depth (e.g., z dimension) or ratio of z dimension to x-y dimension (i.e., "aspect ratio") to provide sufficient capillary force to retain a sample (e.g., a concentrated liquid comprising a sample precipitate) of a given surface tension. The surface energy of the microcavity can be controlled (e.g., modified by a surface treatment) to enhance retention, however, in general, the microcavities of the present disclosure can have an aspect ratio that provides the capillary force necessary to retain the sample of interest.

In some embodiments, the aspect ratio may be at least about 0.1, in some embodiments at least about 0.25, in some embodiments at least about 0.5, in some embodiments at least about 1, in some embodiments at least about 2, in some embodiments at least about 5, and in some embodiments at least about 10. Because in some embodiments the x-y dimension of a microcavity (e.g., a groove) can vary along its depth or z dimension (e.g., if the feature has a draft angle), the aspect ratio can be the ratio of the z dimension to the x-y "representative" dimension. The x-y representative dimension is generally orthogonal to the longitudinal axis of the microcavity and is distinguished from the depth or z dimension of the microcavity. The x-y representative dimensions can be a top dimension (i.e., an x-y dimension at the top opening of the microcavity), a bottom dimension (e.g., an x-y dimension at the base of the microcavity), a middle dimension (e.g., an x-y dimension at a half-depth/height position), an average x-y dimension (e.g., averaged along the depth/height), other suitable representative dimensions, and so forth.

In some embodiments, the x-y representative dimension may be at least about 1 micron, in some embodiments, at least about 10 microns, and in some embodiments, at least about 50 microns. In some embodiments, the x-y representative dimension is less than about 1000 microns, in some embodiments, less than about 500 microns, and in some embodiments, less than about 100 microns.

In some embodiments, the depth or z dimension of the microcavity (i.e., the distance between the closed end or base of the microcavity and the open end or top opening of the microcavity) is at least about 5 micrometers, in some embodiments, at least about 20 micrometers, and in some embodiments, at least about 30 micrometers. In some embodiments, the average depth of the microcavities may be no greater than about 1000 micrometers, in some embodiments, no greater than about 250 micrometers, in some embodiments, no greater than about 100 micrometers, and in some embodiments, no greater than about 50 micrometers.

In some embodiments, the volume of a single microcavity can be at least about 1 picoliter (pL), in some embodiments at least about 10pL, in some embodiments at least about 100pL, and in some embodiments, at least about 1000pL (1 nL). In some embodiments, the microcavity volume can be no greater than about 1,000,000pL (1 μ L), in some embodiments, no greater than about 100,000pL, and in some embodiments, no greater than about 10,000 pL. In some embodiments, the microcavity volume is in the range of 10nL (10,000pL) to 100nL (100,000 pL).

The phrase "substantially transparent" is generally used to refer to an object or substrate that transmits at least 50% of electromagnetic radiation at a selected wavelength or within a selected wavelength range in the ultraviolet to infrared spectrum (e.g., about 200nm to about 1400 nm; "UV-IR"), in some embodiments, at least about 75% of the selected wavelength (or range) in the UV-IR spectrum, and in some embodiments, at least about 90% of the selected wavelength (or range) in the UV-IR spectrum.

The phrase "substantially opaque" is generally used to refer to an object or substrate that transmits less than 50% of electromagnetic radiation at a selected wavelength or within a selected wavelength range in the ultraviolet to infrared spectrum (e.g., about 200nm to about 1400 nm; "UV-IR"), in some embodiments, less than 25% of the selected wavelength (or range) in the UV-IR spectrum, and in some embodiments, less than 10% of the selected wavelength (or range) in the UV-IR spectrum.

Various details of "substantially transparent" and "substantially opaque" are described in PCT patent publication No. WO 2011/063332, which is incorporated herein by reference in its entirety.

The terms "hydrophobic" and "hydrophilic" are generally used in the sense as is commonly understood in the art. Thus, a "hydrophobic" material has a relatively weak or no affinity for water or aqueous media, while a "hydrophilic" material has a relatively strong affinity for water or aqueous media. When used on a variety of hydrophobic or hydrophilic surfaces, the desired level of hydrophobicity or hydrophilicity can vary depending on the nature of the sample, but can be readily adjusted based on simple empirical observation of the liquid sample.

In some embodiments, contact angle measurements (e.g., static and/or dynamic) can be used to characterize the hydrophobicity/hydrophilicity of a surface. Such surface characteristics may contribute to the material composition of the surface itself, possibly independent of bulk material. That is, in some embodiments, even if the bulk material forming the structure is largely hydrophobic, the surface that will contact the sample can be modified to be hydrophilic, such that an aqueous sample, for example, will have a greater affinity for the modified surface. Exemplary static and dynamic contact angle measurement methods are described in examples 10 and 11.

In some embodiments, the static water surface contact angle (e.g., static and/or dynamic) (e.g., as may be determined on a structured surface or on a smooth unstructured surface of the same material) of at least the inner surface of the sample detection container (e.g., where the microcavity of the present disclosure may be formed) may be at least about 50 degrees, in some embodiments at least about 65 degrees, in some embodiments at least about 75 degrees, in some embodiments at least about 85 degrees, in some embodiments at least about 95 degrees, in some embodiments at least about 100 degrees, and in some embodiments, at least about 130 degrees.

In some embodiments, the dynamic advancing surface contact angle (e.g., as may be determined on a structured surface or on a smooth unstructured surface of the same material) of at least the inner surface of the sample detection container (e.g., where the microcavity of the present disclosure may be formed) may be at least about 50 degrees, in some embodiments, at least about 65 degrees, in some embodiments, at least about 75 degrees, in some embodiments, at least about 85 degrees, in some embodiments, at least about 95 degrees, in some embodiments, at least about 100 degrees, and in some embodiments, at least about 130 degrees.

In some embodiments, the dynamic receding surface contact angle (e.g., as may be determined on a structured surface or on a smooth unstructured surface of the same material) of at least the inner surface of the sample detection container (e.g., where the microcavity of the present disclosure may be formed) may be at least about 25 degrees, in some embodiments, at least about 35 degrees, in some embodiments, at least about 45 degrees, in some embodiments, at least about 65 degrees, in some embodiments, at least about 75 degrees, in some embodiments, at least about 90 degrees, and in some embodiments, at least about 100 degrees.

In some embodiments, the interior surface of the sample detection container (e.g., the interior surface of the wall oriented at an effective angle (e.g., at a different location, see example 12)) can have a surface roughness that does not interfere with or improve the collection of the analyte of interest in the microcavity. In some embodiments, the surface roughness of the inner surface may be characterized by an average roughness (Ra) value of less than 1.5 microns, in some embodiments, less than 1 micron, in some embodiments, less than 750nm (0.75 microns), in some embodiments, less than 500nm (0.5 microns), and in some embodiments, less than 300nm (0.3 microns).

In some embodiments, the surface roughness of the interior surface of the sample detection vessel may be characterized by a root mean square roughness (Rq) value of less than 1.5 microns, in some embodiments, less than 1 micron, and in some embodiments, less than 800 nm.

In some embodiments, the systems and methods of the present disclosure can be used to determine the presence or absence of a microorganism of interest in a sample by resolving the sample against the microorganism itself or against an analyte of interest that is representative of the presence of the microorganism. For example, in some embodiments, the microorganisms themselves in the sample can be concentrated (e.g., precipitated by centrifugation into one or more microcavities) and then detected in one or more microcavities, while in some embodiments, the analytes in the sample representative of the presence of the microorganisms can be concentrated (e.g., precipitated by centrifugation into one or more microcavities) and detected in one or more microcavities. For example, in some embodiments, a substrate (e.g., a β -galactosidase substrate, such as X-gal) can be added to the sample, which is precipitated after cleavage by an appropriate enzyme. This precipitated substrate can then be concentrated (e.g., by centrifugation and sedimented into one or more microcavities with the microorganisms/cells) and detected and/or quantified more rapidly than otherwise available for low concentration, large volume samples.

Various examples of analytes are given above and in the examples section, including indicator dyes. In some embodiments, such indicator dyes may comprise a precipitation dye and/or an internalization dye. For precipitating dyes, the dyes are typically small molecules dispersed outside the cell, and may require sufficient incubation time to reach a detectable concentration, even if concentrated in one or more microcavities. However, for internalizing dyes, the cells (i.e., microorganisms) themselves can be "labeled" or stained with the dye, and once the cells are concentrated within the microcavity they can be detected (e.g., presence or absence and/or quantification), for example, by observing the base of the microcavity.

Another specific example of a test that can be performed using the systems and methods of the present disclosure involves detecting microorganisms (e.g., presence or absence) using chemiluminescence by concentrating a sample into one or more microcavities and adding reagents for performing ATP-based detection. The reagents may be added before or after centrifugation, or may be added in the microcavities by coating and/or air drying the reagents. In this embodiment, the reagents may comprise a lysis reagent, luciferin (substrate) and luciferase (enzyme). Lysis reagents may be used to break open cells to release ATP, and luciferase requires ATP to make luciferin chemiluminescence. Thus, the microcavity containing the microorganism of interest will be "labeled" (e.g., will shine) while the microcavity containing no microorganism will not be "labeled" (e.g., will be dark), so that the presence or absence of the microorganism can be directly detected.

Fig. 1 illustrates a sample detection system 100 according to one embodiment of the present disclosure. In some embodiments, the sample detection system 100 can be used to concentrate a sample to form a concentrate (e.g., in the microcavity 136, as shown in fig. 2 and 3 and described in detail below), and can further be used to resolve the concentrate for an analyte of interest, i.e., to detect the presence or absence of the analyte of interest.

As shown in fig. 1, in some embodiments, the sample detection system 100 can include a sample detection container 102. The sample detection container 102 can be configured to be closed with the cap 104 such that the sample detection container 102 and the cap 104 can be removably or permanently coupled together.

The sample detection container 102 can be adapted to contain a sample to be analyzed (e.g., one or more analytes of interest). The sample is typically a liquid sample, in some embodiments, a diluted liquid sample (i.e., any analyte of interest in the sample is present in a low concentration), and in some embodiments, a diluted aqueous sample. The sample detection container 102 may be sized and shaped as desired to contain a sample to be analyzed, and the shape and configuration of the sample detection container 102 and the top cover 104 are shown by way of example only.

As shown in fig. 1, the sample detection container 102 may be an elongated tube having a closed end or base 112 (e.g., a tapered closed end 112) and an open end 114, and the cap 104 may include a closed end or base 116 and an open end 118. Open end 118 of top cover 104 can be sized to receive at least a portion of sample detection container 102, and in particular, open end 114 of sample detection container 102, such that top cover 104 and sample detection container 102 can close and/or cover open end 114 of sample detection container 102 when coupled together.

In general, the sample detection method can be implemented using the sample detection system 100 of fig. 1 as follows: a sample can be placed in the sample detection container 102 and a cap 104 can be coupled to the sample detection container 102 to enclose the sample detection container 102. The closed or capped sample detection container 102 may then be centrifuged toward the closed end 112 of the sample detection container 102 to form, for example, a sample concentrate retained in the microcavity 136 in the sample detection container 102, and a supernatant (e.g., a majority of the supernatant) will be located above the microcavity 136. The separation fluid of the present disclosure may then be added to the sample detection container 102, which is configured to move between the microcavity 136 and a majority of the supernatant to separate the concentrate in the microcavity 136 from the remainder of the sample. The concentrate can then be resolved for the analyte of interest while the concentrate is retained in the sample detection container 102. Thus, in some embodiments, a "concentrate" (i.e., a higher concentration portion of a sample) may also be referred to as a "retentate". In some embodiments, the concentrate can be resolved by: the sample detection container 102 is inverted to expel centrifuged sample supernatant and centrate from the microcavity 136 and to resolve the concentrate in the microcavity 136, for example, through the closed end 112 of the sample detection container 102.

One exemplary sample testing method that employs the sample testing container 102 is described in more detail below in conjunction with FIG. 4.

By way of further example, the top cover 104 includes an inner surface 120 that includes one or more protrusions 121, and the sample detection container 102 includes an outer surface 122 that includes one or more tracks or threads 123 adjacent the open end 114. The protrusion 121 of the top cover 104 is configured to mate with and engage the threads 123 of the sample detection vessel 102 such that the top cover 104 and the sample detection vessel 102 can be coupled together.

The particular pattern of protrusions 121 and threads 123 shown in fig. 1 includes a series of circumferentially spaced protrusions 121 and threads 123 such that any protrusion 121 on the top cover 104 can be coupled to any thread 123 on the sample detection container 102 and rotated from an unlocked position to a locked position by rotating the top cover 104 and the sample detection container 102 relative to each other (e.g., 90 degrees if 4 sets of protrusions 121/threads 123 are used and the 4 sets of protrusions/threads are evenly spaced around the inner surface 120 of the top cover 104 and the outer surface 122 of the sample detection container 102). The coupling mechanism shown between the sample detection container 102 and the top cover 104 is shown by way of example only as an effective means for closing the sample detection container 102.

In some embodiments, the sample detection container 102 and the cap 104 can be coupled together in a manner such that the interior of the sample detection system 100 is sealed from the environment (e.g., forming a liquid-tight seal, a gas-tight seal, or a combination thereof). For example, in some embodiments, one or more seals (e.g., O-rings) may be employed between the sample detection container 102 and the cap 104, or one or both of the sample detection container 102 and the cap 104 may include one or more seals (e.g., O-rings).

The sample detection vessel 102 and the top cover 104 can be formed from a variety of materials including, but not limited to, polymeric materials, metals (e.g., aluminum, stainless steel, etc.), ceramics, glass, and combinations thereof. Examples of polymeric materials may include, but are not limited to, polyolefins (e.g., polyethylene, polypropylene, combinations thereof, and the like), polycarbonates, acrylics, polystyrenes, High Density Polyethylene (HDPE), polypropylene, other suitable polymeric materials capable of being formed into a self-supporting container, or combinations thereof. The term "self-supporting" is generally used to refer to an object that does not collapse or deform under its own weight. For example, a bag is not "self-supporting" if it cannot maintain its shape under its own weight, but rather collapses or deforms. The sample detection container 102 and the top cover 104 may be formed of the same material or different materials.

The sample detection container 102 and the cap 104, or portions thereof, may be substantially transparent, non-transparent (i.e., substantially opaque), or intervening (e.g., translucent), and may be of any suitable size, depending on the type, amount, and/or size of the sample to be analyzed and the type, amount, and/or size of the concentrate to be collected and resolved. The sample detection container 102, or at least the portion adjacent to the microcavity 136, is preferably substantially transparent. In some embodiments, the sample detection container 102 can have a capacity of at least about 1mL, at least about 5mL, at least about 10mL, at least about 25mL, at least about 50mL, at least about 100mL, or at least about 250 mL. That is, in some embodiments, the capacity or volume of the sample detection container 102 may be in the range of about 1mL to about 250mL, and in some embodiments, may be in the range of about 1mL to about 100 mL.

The shape, size and coupling means of the sample detection container 102 and the top cover 104 are described above and shown in fig. 1 by way of example only. However, it should be understood that the sample detection container 102 and the top cover 104 can take a variety of shapes and sizes. Additionally, sample detection container 102 and top cover 104 can be removably and/or permanently coupled together using a variety of coupling means including, but not limited to, threads (as shown in the figures or otherwise), clamps (e.g., spring-loaded clamps, snap-type clamps, etc.), clips (e.g., spring-loaded clamps, etc.), ties (e.g., cable ties), one or more magnets, tape, adhesives, glues, snap-fit joints (e.g., where top cover 104 functions as a flip-top), press-fit joints (also sometimes referred to as "friction fit joints" or "interference fit joints"), thermal bonds (e.g., heat and/or pressure applied to one or both components to be coupled), welds (e.g., sonic (e.g., ultrasonic) welds), other suitable coupling means, and combinations thereof.

As shown in fig. 2 and 3, the closed end 112 of the sample detection container 102 may include (i.e., terminate at) one or more micro-cavities 136 adapted to retain sample concentrate to be analyzed, the micro-cavities 136 opening toward the open end 114 of the sample detection container 102. The microcavity 136 can include at least one of a hole, a depression, a groove, and the like, and combinations thereof, such that the microcavity 136 defines an interior volume (e.g., a microscale volume or smaller) configured to retain sample concentrate. In some embodiments, as shown in fig. 1-3, 4, and 5, the sample detection container 102 can include a single microcavity 136. In some embodiments, the sample detection container 102 may include a plurality of microcavities 136. In some embodiments, the number of microcavities 136 can be minimized in order to minimize the total volume of sample concentrate that can be retained, thereby maximizing the concentration of the analyte of interest (if present) in the retained sample concentrate.

In some embodiments, the sample detection container 102 can include one or more protrusions 143 surrounding the microcavity 136. Such protrusions or support structures 143 can be used to support the microcavity (or microcavities) 136 during formation and use, particularly when a single microcavity or several microcavities are employed.

In some embodiments, a large number of microcavities 136 may be employed, for example, to increase the probability that only one analyte of interest (e.g., 1 colony forming unit (cfu) of bacteria of interest) will reside in a given microcavity 136. This configuration is particularly useful for quantifying the amount of an analyte of interest present in a given sample. These microcavities can then be scanned, for example, to determine the presence or absence of an analyte of interest, while characterizing the amount of analyte present. However, the inventors have found that if at most one (or a relatively small amount) of the analyte of interest is present in a given microcavity 136, the concentration in that microcavity 136 may be relatively low, resulting in a longer time required to detect the sample. For example, if a sample contains 10cfu of bacteria of interest, and each of the 10cfu stays in a separate microcavity 136, it will take longer to detect the presence of the bacteria of interest than if all 10cfu stays in the same microcavity 136.

Thus, the inventors have found that if the number of microcavities can be minimized, then all analytes of interest that may be present in the sample will be more likely to be concentrated together in a smaller total or overall volume in a smaller number of microcavities 136, resulting in a higher concentration and even a shorter detection time. However, the previous teachings suggest a departure from this configuration, as minimizing the number of microcavities would diminish or eliminate (i.e., lose) the ability to quantify the analyte of interest. This can greatly reduce the detection time used to determine the presence or absence of the analyte of interest. To this end, a single microcavity 136 may be utilized to achieve certain advantages if quantification of the analyte of interest is not particularly desired. If quantification is desired, the sample detection container of the present disclosure may include multiple microcavities to facilitate quantification.

Thus, in some embodiments, the sample detection container 102 can include no more than 10 microcavities, in some embodiments, no more than 8 microcavities, in some embodiments, no more than 5 microcavities, in some embodiments, no more than 4 microcavities, in some embodiments, no more than 3 microcavities, in some embodiments, no more than 2 microcavities, and in some embodiments, no more than 1 microcavity. For simplicity, the microcavities 136 of fig. 1-3, 4 and 5 are depicted as a single microcavity, but it should be understood that this description applies to multiple microcavities 136 if more than one microcavity is employed.

As shown in fig. 3, in some embodiments, the microcavity 136 can include an open end (open or top-opening) 144, one or more sidewalls 142, a base 146, and a longitudinal axis a. As shown in fig. 1 and 2, the longitudinal axis a of the microcavity 136 can also be the longitudinal axis a of the sample detection container 102 and the sample detection system 100. In some embodiments, as shown, the microcavity 136, the sample detection container 102, and the cap 104 are centered about the longitudinal axis a. The longitudinal axis a is generally perpendicular to a cross-section of the microcavity 136 (i.e., orthogonally oriented relative to the cross-section of the microcavity) and may pass through the top opening 144 and the base 146 of the microcavity 136. Such a cross-section of the microcavity 136 can be taken anywhere along the height of the microcavity 136 between its top opening 144 and base 146. The longitudinal axis a may also be referred to as the vertical axis or nominal centrifugation/sedimentation axis, i.e., the axis along which a sample located in the sample detection container 102 is subjected to centrifugal force when centrifuged (without regard to the known effects of small radius (i.e., bench top) centrifuges). Other possible shapes and configurations of the microcavity 136 are shown in fig. 3A-3C and described in more detail below.

The microcavity 136 shown in FIG. 3 has a generally trapezoidal cross-sectional shape (i.e., a truncated conical three-dimensional shape). It should be understood that the microcavity 136 can include a variety of shapes, so long as the shape of the microcavity 136 is capable of retaining sample concentrate. In other words, each recess 136 may be shaped and sized to provide a receptacle or well for the sample concentrate. In general, the microcavity 136 is configured (e.g., shaped and sized) to retain the concentrate 154 in the microcavity 136 (e.g., by capillary forces) when the sample detection container 102 is in any orientation.

Regardless of whether the microcavity 136 includes holes, recesses, or a combination thereof, examples of suitable groove shapes can include, but are not limited to, a variety of polyhedral shapes, parallelepipeds, pseudo-cylinders, prisms, and the like, as well as combinations thereof. For example, the microcavity 136 may be a polyhedron, a cone, a truncated cone, a pyramid, a truncated pyramid, a sphere, a partial sphere, a hemisphere, an ellipsoid, a dome, a cylinder, a cube corner, other suitable shapes, and combinations thereof. Further, the microcavity 136 can have a variety of cross-sectional shapes (including a vertical cross-section, a horizontal cross-section, or a combination thereof, as shown in FIG. 3), including but not limited to: at least one of a parallelogram, a parallelogram with rounded corners, a rectangle, a square, a circle, a semicircle, an ellipse, a semi-ellipse, a triangle, a trapezoid, a star, other polygons, other suitable cross-sectional shapes, and combinations thereof.

As shown in fig. 1-3, the sample detection container 102 can further include a wall 138 (i.e., an inner wall) that defines at least a portion of an inner surface of the sample detection container 102. The wall 138 extends to the microcavity 136 (e.g., tapers toward the microcavity), and at least a portion of the wall 138 is located adjacent to the top opening 144 of the microcavity 136. Generally, the phrase "located adjacent to the top opening of the microcavity" refers to the fact that the wall 138 (or a portion thereof) extends all the way to the top opening 144 of the microcavity 136 (as shown), or all the way to a location that is less than 1 times (preferably less than 0.5X or less than 0.25X) the lateral dimension (i.e., the representative dimensions X, y as described above) of the microcavity 136. In some embodiments, a representative lateral dimension may be the lateral dimension of the microcavity 136 at its top opening 144.

At least a portion of the wall 138 is inclined toward the microcavity 136 and has an inclination oriented at an effective angle α relative to the longitudinal axis a of the microcavity 136. The effective angle α may generally be in the range of 0 to 90 degrees. As discussed above, an upper limit of 90 degrees may facilitate collection of any analyte of interest in microcavity 136. That is, the effective angle α can be configured to maximize the amount of sample collected and deposited into the microcavity 136 such that, under centrifugation, an analyte of interest (e.g., a microorganism) will be directed into the microcavity 136. As illustrated by the embodiments, effective angles a of 45 degrees and 60 degrees were tested using the systems and methods of the present disclosure. However, the inventors have found that the performance of the disclosed systems and methods employing a separation liquid is not dependent on the effective angle.

Wall 138 (and in particular its effective angle α) may facilitate collection of an analyte of interest in microcavity 136 and facilitate obtaining a concentration of the analyte of interest in microcavity 136. In some embodiments, the wall 138 (e.g., the area of the wall 138) may be significantly larger relative to the microcavity 136 (e.g., relative to the open area of the microcavity 136). Thus, the length of at least a portion of the wall 138 oriented at the effective angle α (and located adjacent to the microcavity 136) (see, e.g., length L of fig. 3) can be at least 5 times a representative dimension of the microcavity 136 (e.g., a dimension oriented orthogonally relative to the longitudinal axis a). For example, in some embodiments, the length of the wall 138 (or a related portion of the wall oriented at the effective angle α) may be 5 times the transverse dimension (e.g., at the top opening 144). FIG. 3 shows the transverse dimension X at the top opening 144 of the microcavity 136. As further shown in fig. 3, the portion of the length L of the wall 138 that is clearly shown is at least 5X.

In some embodiments, the length of the wall 138 may be at least 10X, in some embodiments at least 15X, in some embodiments at least 20X, in some embodiments at least 50X, in some embodiments at least 100X, in some embodiments at least 200X, in some embodiments at least 500X, and in some embodiments at least 1000X.

The lateral dimensions (i.e., x, y) of the top opening are generally used as representative lateral dimensions in this disclosure, as this is the interface location between the wall 138 and the microcavity 136. However, other dimensions may also be used as representative dimensions, provided that the representative dimensions are capable of indicating an order of magnitude of microcavity 136 relative to the wall length. For example, in some embodiments, the base 146 of the microcavity 136 may be used (e.g., a flat base if employed), or an average lateral dimension taken over the height of the microcavity 136 may be used, and so forth.

In some embodiments, as shown in fig. 3, the microcavity 136 can include a draft angle β such that one or more sidewalls 142 of the microcavity 136 are oriented at a non-zero and non-right angle relative to the respective base 146. In some embodiments, the draft angle β may be expressed as the angle between the sidewalls 142 of the microcavity 136 and the vertical direction (i.e., a line or plane perpendicular or orthogonal to the flat base 146). In some embodiments, the draft angle β may be at least about 5 degrees, in some embodiments, at least about 10 degrees, in some embodiments, at least about 12.5 degrees, and in some embodiments, at least about 15 degrees. In some embodiments, the draft angle β is not greater than about 50 degrees, in some embodiments, not greater than about 30 degrees, in some embodiments, not greater than about 25 degrees, and in some embodiments, not greater than about 20 degrees. In some embodiments, the draft angle β is in the range of about 10 degrees to about 15 degrees. In some embodiments, the draft angle β is 14 degrees.

In the embodiment shown in fig. 3, the base 146 of the microcavity 136 is flat and planar (i.e., has an area), and is oriented substantially orthogonally with respect to the longitudinal axis a. However, since other shapes for microcavity 136 are possible, base 146 need not be planar, but may include a point or line having the greatest spacing from top opening 144. Further, even in embodiments employing a planar base 146, the base 146 need not be completely flat, but may be at least partially curved, flat, or a combination thereof. Furthermore, even in embodiments employing a flat planar base 146, the base 146 need not be orthogonal to the longitudinal axis a.

Further, in the embodiment shown in fig. 3, the microcavities 136 are shown as having different lines of symmetry, and the base 146 is centered with respect to the opening 144. However, it should be understood that the microcavity 136 need not include any line of symmetry, and the base 146 (whether or not the base 146 includes a point, line, or plane) need not be centered with respect to the opening 144 of the microcavity 136.

If more than one microcavity 136 is employed, the microcavities 136 may be of the same size and shape; however, it should be understood that all microcavities 136 need not be the same size or shape. That is, the microcavities 136 may each be formed of substantially the same shape and size, the same or similar shape but different size, different shape but similar size, different shape and size, or a combination thereof.

Fig. 3A-3C show close-up views of sample detection containers 102A,102B, and 102C according to further embodiments of the present disclosure. Sample detection containers 102A,102B,102C each include a microwell 136A,136B,136C, a longitudinal axis a ', a ", a'", and a wall 138A,138B,138C oriented at an effective angle α ', α ", a'", respectively.

FIG. 3A illustrates a sample detection vessel 102A in which the wall 138A is curved such that it includes multiple inclinations, for example, for illustrative purposes, effective angles α', α are shown₂’,α₃'. However, the portion of wall 138A located adjacent to microcavity 136A is at least as great as the transverse dimension X of the top opening 144A of microcavity 136ABy a factor of 5, and a plurality of inclinations of the curved wall 138A (i.e., a plurality of effective angles α ', α ", α"') are each greater than 45 degrees and less than 90 degrees, thus, fig. 3A demonstrates that the "wall" of a sample detection container according to the present disclosure can be curved or can include a plurality of inclinations.

Fig. 3B shows a sample detection container 102B (or wall 138) that includes a flat region (i.e., oriented at 90 degrees relative to the longitudinal axis a ") between the wall 138 (or a portion of the wall oriented at an effective angle a") and the microcavity 136. However, the flat region is not significantly dimensioned relative to either microcavity 136 or wall 138, and has a length R that is less than 1 times, in some embodiments, less than 0.5X, and in some embodiments, less than 0.25X, the transverse dimension X of microcavity 136B at top opening 144B. The sample detection container 102 is substantially identical to the sample detection container 102 of fig. 1-3, except for a flat region.

Fig. 3C shows microcavity 136C with a rounded bottom and a rounded top opening. Inflection point I defines where microcavity 136C meets wall 138C or a portion of the wall oriented at an effective angle α' ", for example. As shown, in some embodiments, the inflection point I may define the top opening 144C of the microcavity 136C, and thus, in such embodiments, the lateral dimension X of the microcavity 136C may be taken at the height of the inflection point I. Such curved upper surfaces of the microcavities 136C can be formed from a molded workpiece. In general, however, if the walls of the sample detection container of the present disclosure are described as being oriented at an effective angle α, the dimensions of such "walls" (e.g., wall 138C) of the present disclosure are sufficiently large relative to the microcavity 136 such that the wall 136C is not merely a molded piece.

With continued reference to the embodiments of fig. 1-3, in some embodiments, the microcavity 136 (e.g., relative to the remainder of the sample detection container 102) can include a surface modification (e.g., a hydrophilic/lipophilic surface treatment or coating) that facilitates retention of the concentrate of interest.

In some embodiments, as shown, the sample detection container 102 may be described as including a microcavity 136 in a first side 140 of the sample detection container 102, which generally faces the interior (or "inside") of the sample detection container 102, and generally includes the interior surface 124 of the sample detection container 102, or a portion thereof. Specifically, first side 140 may include inner surface 124, in which microcavity 136 may be formed such that top opening 144 of microcavity 136 opens toward first side 140 of sample detection container 102 and toward the interior of sample detection container 102. The sample detection container 102 can also include a second side 141 (see, e.g., fig. 3) having an outer surface 149 that is generally opposite the first side 140 and the inner surface 124, respectively. The second side 141 may face the outside of the sample detection container 102, e.g., away from the sample detection container 102. Thus, the concentrate retained in the sample detection container 102 (i.e., the microcavity 136) can be resolved from the second side 141, such as in embodiments where at least a portion of the sample detection container 102 (e.g., the closed end or base 112 and/or the second side 141) is substantially transparent.

As described above, in some embodiments, the volume of the sample detection container 102 (i.e., the volume of the sample detection container 102) may be in the range of about 1mL to about 250 mL. Thus, in some embodiments, the volume of the sample may be at least about 1mL, in some embodiments, at least about 10mL, and in some embodiments, at least about 100 mL. In some embodiments, the volume of the sample is no greater than about 200mL, in some embodiments, no greater than about 100mL, in some embodiments, no greater than about 75mL, and in some embodiments, no greater than about 50 mL. In some embodiments, the volume of the sample ranges from about 1mL to about 100 mL.

In some embodiments, the sample detection container 102 has a capacity to retain a volume of concentrate, and/or the collection volume of the plurality (if employed) of microcavities 136 (or microcavity surfaces) is at least about 1 microliter (μ L), in some embodiments at least about 5 μ L, in some embodiments at least about 10 μ L, and in some embodiments, at least about 25 μ L. In some embodiments, the sample detection container 102 has a capacity to retain a volume of concentrate, and/or the collection volume of the plurality (if employed) of microcavities 136 (or microcavity surfaces) is no greater than about 200 μ L, in some embodiments, no greater than about 100 μ L, in some embodiments, no greater than about 75 μ L, and in some embodiments,not greater than about 50 μ L. In some embodiments, the sample detection container 102 has a capacity to retain a volume of concentrate, and/or the collection volume of the plurality of microcavities 136 (or microcavity surfaces) is in the range of about 1 μ Ι _ to about 100 μ Ι _. In some embodiments, these volumes can be expressed as a volume per unit area (e.g., μ L/cm)²) Such that the collection volume of the microcavity surface may be independent of the overall size of the sample detection vessel 102.

In some embodiments, the ratio of the volume of the sample detection container 102 (or the "receiver" portion of the container 108) to the volume of sample concentrate (or retentate) retained in the microcavity 136 is at least about 100:1 (10)²1), and in some embodiments, at least about 1000:1 (10)³1), and in some embodiments, at least about 10,000:1 (10)⁴1), and in some embodiments, at least about 100,000:1 (10)⁵1); in some embodiments, at least about 10⁸1, preparing a catalyst; in some embodiments, at least about 10⁹1, preparing a catalyst; in some embodiments, at least about 10¹⁰1, preparing a catalyst; and in some embodiments, at least about 10¹¹:1. In some embodiments, the ratio of the volume of the sample detection container 102 to the volume of the concentrate in the microcavity 136 is between about 100:1 and about 10¹¹1 in the range of.

In some embodiments, the concentration increase (i.e., the concentration of the resulting concentrate (e.g., the concentration of the denser species, such as the analyte of interest) retained in the microcavity 136 divided by the concentration of the initial sample, expressed as a ratio) can be at least about 100:1 (10)²1), and in some embodiments, at least about 1000:1 (10)³1), and in some embodiments, at least about 10,000:1 (10)⁴1), and in some embodiments, at least about 100,000:1 (10)⁵:1). In some embodiments, the concentration efficiency is from about 10:1 to about 10⁵1 in the range of.

Referring to fig. 4, a sample detection method 150 will now be described with continued reference to the sample detection system 100 of fig. 1-3, wherein the microcavity 136 is schematically illustrated for purposes of illustration.

As shown in FIG. 4, in a first step 150AThe sample 152 can be positioned in a sample test and the cap 104 can be coupled to the sample test container 102 to enclose the sample test container 102. As shown in a second step 150B, a first direction (or orientation) D may be toward the microcavity 136₁The sample detection system 100 (i.e., the sample detection container 102) is centrifuged. This centrifugation process may form a concentrate 154 and a supernatant 156 of the sample 152, and may displace the concentrate 154 (see FIG. 5) containing the denser material of the sample 152 into the microcavity 136. The "concentrate" 154 may generally include a sample precipitate formed by the centrifugation process, but may also include at least some supernatant or diluent of the sample, as will be described in detail below with reference to fig. 5.

In the centrifugation step illustrated in step 150B of fig. 4, the g-force of centrifugation, duration, and/or number of cycles required to form and retain the concentrate 154 in the microcavity 136 can vary depending on one or more of the composition of the sample 152, the analyte of interest, and the like. In some embodiments, the amount of g-force required to concentrate an analyte of interest may depend on the size and density of the analyte, the density and viscosity of the diluent, and the volume of sample 152 in sample detection container 102 (i.e., the height of sample 152 in sample detection container 102 defines the distance required for the analyte to migrate to reach microcavity 136 under a given g-force). The settling velocity (V, in centimeters per second (cm/s)) can be approximated by equation 1:

V＝2ga²(ρ1-ρ2)/9η (1)

wherein g is in cm/s²Acceleration (i.e., in gs 980 cm/s)²G force of (g)) ρ 1 is in g/cm³The density of the analyte of (1), ρ 2 ═ g/cm³The density of the sample medium (e.g., diluent), η, is the viscosity coefficient in poise (g/cm/s), and a is the analyte radius in centimeters (assuming a spherical shape.) in some centrifuges, the g-force may be determined by the rotational speed (e.g., in Revolutions Per Minute (RPM)) and the distance of the sample from the center of the rotor (i.e., the greater the g-force the sample is subjected to if the sample location is located farther from the rotor location at the same rotational speed), and therefore, in order to collect the analyte of interest in the sample 152 that may be located farthest from the microcavity 136The distance between the center of the rotor and the height of the sample 152 disposed closest to the rotor can be calculated to estimate how much g-force will be required to move the analyte of interest the furthest distance in the sample 152, thereby maximizing the amount of analyte of interest collected.

The sedimentation velocity can be calculated using the above formula, and the centrifugation time (i.e., duration) can then be calculated by dividing the distance (e.g., maximum distance) that the analyte of interest (if present) will need to travel by the sedimentation velocity. Alternatively, the desired time and distance may be used to estimate the settling velocity, and then the required g-force may be calculated using equation 1.

In some embodiments, the g-force in the centrifugation step may be at least about 500-g (e.g., 500x 9.8m/s on the ground at sea level height²) In some embodiments, at least about 1000 g, and in some embodiments, at least about 5000 g. In some embodiments, the g-force in the centrifugation step may be no greater than about 100,000-g, in some embodiments, no greater than about 50,000-g, and in some embodiments, no greater than about 10,000-g.

In some embodiments, the duration of the centrifugation step may be at least about 1 minute, in some embodiments, at least about 5 minutes, and in some embodiments, at least about 10 minutes. In some embodiments, the duration of the centrifugation step may be no greater than about 120 minutes, in some embodiments, no greater than about 60 minutes, and in some embodiments, no greater than about 20 minutes.

One or more separation fluids 157 may then be added to the sample detection vessel 102, as shown in step 150C of fig. 4. For example, the cap 104 can be temporarily removed from the sample detection vessel 102 to add the separation liquid 157, and then the sample detection system 100 can be re-closed by coupling the cap 104 to the sample detection vessel 102.

As shown in step 150C of fig. 4, the separation liquid 157 effectively displaces the supernatant 156 from the microcavity 136 outside of the microcavity 136 (i.e., above the top opening 144 of the microcavity 136) such that the concentrated liquid 154 of the sample 152 is retained and separated in the microcavity 136. That is, the separation liquid 157 moves between the sample 152 concentrate 154 located in the microcavity 136 and the sample remainder in the sample detection container 102, such that the separation liquid 157 effectively separates the concentrate 154 contained in the microcavity 136 from a substantial portion of the supernatant 156 of the sample 152.

Thus, at step 150C of the method 150 of fig. 4, the separation liquid 157 is located in the sample detection vessel 102 above the microcavity 136. Surprisingly, the separation liquid 157 has the ability to effectively separate the concentrate 154 from the bulk of the supernatant 156 without disrupting the concentrate 154 in the microcavity 136. That is, the inventors have discovered that the separation liquid 157 can be used to separate the concentrate 154 from the supernatant 156 in the microcavity 136 while maintaining the ability of the microcavity 136 to retain the concentrate 154, i.e., without increasing the volume of the concentrate 154, which would cause a decrease in the concentration of the analyte of interest and an increase in the detection time. Furthermore, because the separation liquid 157 can effectively separate the concentrate 154, there is no need to remove the supernatant 156 and the separation liquid 157 from the sample detection vessel 102, nor to suck the supernatant and the separation liquid away from the microwells 136 (e.g., by inverting the sample detection vessel 102). This method of removing the supernatant 156 and/or the separation liquid 157 is still possible, but not required when rapidly detecting the analyte of interest in the microcavity 136.

The ability of the separation liquid 157 to effectively separate the concentrate 154 from the bulk of the supernatant 156 may be due, at least in part, to the separation liquid 157 having a density sufficient to allow the separation liquid 157 to move down to the bottom of the sample detection vessel 102 (i.e., toward the microcavity 136) to displace the supernatant 156 and having a sufficient interfacial tension (i.e., liquid-liquid interfacial tension) with the sample 152, and particularly with the supernatant 156 of the sample 152. The ability of the separation liquid 157 to separate the concentrate 154 in the microcavity 136 without disrupting the concentrate 154 may also be due, at least in part, to the interfacial tension between the separation liquid 157 and the sample 152 (i.e., the supernatant 156).

Sufficient interfacial tension between the separation liquid 157 and the sample 152 (i.e., the supernatant 156) can ensure proper separation between the separation liquid 157 and the supernatant 156 (both located at the microcavity 136 and in the bulk of the liquid above the microcavity 136). In other words, sufficient interfacial tension between the separation liquid 157 and the sample 152 (i.e., the supernatant 156) can ensure proper separation of the concentrate 154 in the microcavity 136 from the bulk of the liquid (i.e., the supernatant 156) above the microcavity 136.

In particular, the separation liquid 157 may have a density greater than the supernatant 156 of the sample 152 (i.e., the majority of the supernatant located outside of the microcavity 136). In some embodiments, the separation liquid 157 can have a density greater than water (e.g., for aqueous samples), in particular, the separation liquid 157 can have a density of at least 1.2g/mL (or g/cm)³). In some embodiments, the separation liquid 157 may have a density of at least 1.3g/mL, in some embodiments, at least 1.4g/mL, in some embodiments, at least 1.5g/mL, in some embodiments, at least 1.6g/mL, in some embodiments, at least 1.7g/mL, in some embodiments, at least 1.8g/mL, in some embodiments, at least 1.9g/mL, and in some embodiments, at least 2.0 g/mL. In some embodiments, the density of the separation liquid 157 may be no greater than 3.0g/mL, in some embodiments, no greater than 2.8g/mL, in some embodiments, no greater than 2.5g/mL, in some embodiments, no greater than 2.3g/mL, and in some embodiments, no greater than 2.0 g/mL. In some embodiments, the density of the separation liquid 157 is in the range of 1.2g/mL to 1.94 g/mL. In some embodiments, the density of the separation liquid 157 is in the range of 1.4g/mL to 1.94 g/mL.

In other words, in some embodiments, the density of the separation liquid 157 can be at least 0.2g/mL, in some embodiments at least 0.3g/mL, in some embodiments at least 0.4g/mL, in some embodiments at least 0.5g/mL, in some embodiments at least 0.6g/mL, in some embodiments at least 0.7g/mL, in some embodiments at least 0.8g/mL, in some embodiments at least 0.9g/mL, in some embodiments at least 1.0g/mL greater than the density of the sample 152 (i.e., the supernatant 156). In some embodiments, the density of the separation liquid 157 may be no more than 2.0g/mL, in some embodiments, no more than 1.8g/mL, in some embodiments, no more than 1.5g/mL, in some embodiments, no more than 1.3g/mL, and in some embodiments, no more than 1.0g/mL greater than the density of the sample 152 (i.e., the supernatant 156). In some embodiments, the density of the separation liquid 157 may be 0.2g/mL to 0.94g/mL greater than the density of the sample 152 (i.e., the supernatant 156). In some embodiments, the density of the separation liquid 157 may be 0.4g/mL to 0.94g/mL greater than the density of the sample 152 (i.e., the supernatant 156).

For aqueous samples 152, the density of the separation liquid 157 may be at least 0.2g/mL, in some embodiments at least 0.3g/mL, in some embodiments at least 0.4g/mL, in some embodiments at least 0.5g/mL, in some embodiments at least 0.6g/mL, in some embodiments at least 0.7g/mL, in some embodiments at least 0.8g/mL, in some embodiments at least 0.9g/mL, and in some embodiments at least 1.0g/mL greater than the density of water. In some embodiments, the density of the separation liquid 157 may be no more than 2.0g/mL greater than the density of water, in some embodiments no more than 1.8g/mL greater, in some embodiments no more than 1.5g/mL greater, in some embodiments no more than 1.3g/mL greater, and in some embodiments no more than 1.0g/mL greater. In some embodiments, the density of the separation liquid 157 may be from 0.2g/mL to 0.94g/mL greater than the density of water. In some embodiments, the density of the separation liquid 157 may be 0.4g/mL to 0.94g/mL greater than the density of water.

Furthermore, the interfacial tension (i.e., liquid-liquid interfacial tension) of the separation liquid 157 with the sample 152, and particularly with the supernatant 156, can be at least 50 dynes/cm (0.05N/m); in some embodiments, at least 52 dynes/cm (0.052N/m); in some embodiments, at least 55 dynes/cm (0.055N/m); in some embodiments, at least 56 dynes/cm (0.056N/m); in some embodiments, at least 60 dynes/cm (0.06N/m); in some embodiments, at least 65 dynes/cm (0.065N/m).

In some embodiments, the surface tension of the separation liquid 157 may be no greater than 20 dynes/cm (0.02N/m); in some embodiments, no greater than 19 dynes/cm (0.019N/m); in some embodiments, no greater than 18 dynes/cm (0.018N/m); in some embodiments, no greater than 17 dynes/cm (0.017N/m); in some embodiments, no greater than 16 dynes/cm (0.016N/m); in some embodiments, no greater than 15 dynes/cm (0.015N/m); in some embodiments, no greater than 10 dynes/cm (0.01N/m).

In some embodiments, the interfacial tension between the separation liquid 157 and the sample 152 (e.g., supernatant 156) can be estimated by calculation (i.e., by subtracting the surface tension of the separation liquid 157 from the surface tension of the sample 152 (e.g., supernatant 156)).

In some embodiments, if the sample 152 is aqueous, the interfacial tension between the separation liquid 157 and the sample 152 (or supernatant 156) can be estimated by finding or calculating the interfacial tension between the separation liquid 157 and water. For example, in some embodiments, the interfacial tension between the separation liquid 157 and water may be at least 50 dynes/cm (0.05N/m); in some embodiments, at least 52 dynes/cm (0.052N/m); in some embodiments, at least 55 dynes/cm (0.055N/m); in some embodiments, at least 56 dynes/cm (0.056N/m); in some embodiments, at least 60 dynes/cm (0.06N/m); and in some embodiments, at least 65 dynes/cm (0.065N/m).

Furthermore, it may be necessary to minimize diffusion and/or dissolution of the sample 152 (e.g., the precipitate or any analyte of interest and/or the supernatant 156) in the separation liquid 157, and vice versa. For example, in some embodiments, the separation liquid 157 can have a solubility in the sample 152 (e.g., the supernatant 156) of less than 1% (or 10,000ppm), in some embodiments, less than 0.1% (or 1,000ppm), and in some embodiments, less than 0.01% (or 100 ppm).

For aqueous samples 152, the separation liquid 157 is characterized by a solubility in water of less than 1% (or 10,000ppm), in some embodiments, less than 0.1% (or 1,000ppm), and in some embodiments, less than 0.01% (or 100 ppm).

In some embodiments, the solubility of the sample 152 (or water) in the separation liquid 157 can be less than 1% (or 10,000ppm), in some embodiments less than 0.1% (or 1,000ppm), and in some embodiments, less than 0.01% (or 100 ppm).

As described above, the separation liquid 157 may also be non-toxic and inert to the sample detection system (including the sample detection vessel 102, the sample 152, and any analyte of interest that may be present in the sample 152).

In some embodiments, the separation liquid 157 may also be colorless to provide (and not interfere with) multiple resolution methods for resolving the microcavity 136. For example, for some types of detection (e.g., fluorescence), the separation liquid 157 can be configured to allow excitation of the microcavity 136 from above (i.e., through the separation liquid 157), from below, and/or from the side, as well as detection of the microcavity from above, from below, and/or from the side.

The phrase "colorless" is generally used to refer to an object or substrate that transmits at least 50% of electromagnetic radiation at a selected wavelength or within a selected wavelength range in the ultraviolet (e.g., about 200nm to about 400 nm; "UV") spectrum and/or the visible (e.g., about 400nm to about 700 nm; "Vis") spectrum; in some embodiments, at least about 75% of selected wavelengths (or ranges) in the UV and/or Vis spectra are transmitted; and in some embodiments, at least about 90% of selected wavelengths (or ranges) in the UV and/or Vis spectra are transmitted.

In some embodiments, the separation liquid 157 may comprise a liquid comprising fluorocarbons, fluorocarbon derivatives, perfluorinated compounds, other suitable mixtures, or combinations thereof; other liquids that meet the limitations of the present disclosure; or a combination thereof. Examples of fluorocarbon based liquids may include 3M under the trade name^TMFLUORINERT^TM(electronic liquid available from 3M Company (st. paul, MN), st paul, MN, usa); under the trade name 3M^TMNOVEC^TMEngineering fluids available from (3M Company)); under the trade name ofFluorinated oils available from DuPont, Wilmington, DE, Wilmington, Del.A.; other suitable fluorocarbon-based liquids; or of themAnd (4) combining. Generally, a "perfluorinated compound" is an organofluorine compound in which all of the hydrogens on the carbon chain are replaced with fluorine, wherein the molecule further comprises at least one different atom or functional group. Generally, a "fluorocarbon" is a compound formed by replacing one or more hydrogen atoms in a hydrocarbon with a fluorine atom. Fluorocarbons are sometimes referred to as perfluorocarbons.

As shown in step 150D of fig. 4, the concentrate 154 in the microcavity 136 can then be resolved (e.g., optically resolved) from outside or exterior to the sample detection container 102 (i.e., from the second side 141 of the sample detection container 102, as represented by the large arrow). The large arrow is shown pointing vertically upward toward the microcavity 136 (i.e., toward its base 146), but it should be understood that the microcavity 136 may be resolved from any desired direction (e.g., including through the separation liquid 157). As described above, the sample detection container 102, or at least a portion thereof, can be colorless so as to enable resolution (e.g., optical resolution) of the concentrate 154 from the second side 141. In addition, such embodiments may employ sample detection container 102 and cap 104 that are permanently coupled together, as the detection or resolving step may be performed from the outside of sample detection system 100, such that it is not necessary to separate cap 104 from sample detection container 102 for the resolving step. Additionally, in such embodiments, as shown in step 150D of fig. 4, the supernatant 156 and the separated liquid 157 remain above the microcavity 136, which can avoid substantial evaporation of the concentrate 154 before the detection/resolution process is complete.

The resolution of the concentrate 154 can include any of the detection methods described above for detecting an analyte of interest in a sample, including optical resolution methods such as optical scanning, imaging, or any of the other methods described above. For example, fluorescence detection may include directing electromagnetic energy toward the concentrate 154 in the microcavity 136 at a first frequency and detecting electromagnetic energy emitted from the concentrate 154 in the microcavity 136 at a second frequency. By way of further example, colorimetric detection may include emitting a broad range of frequencies of electromagnetic energy (i.e., broad spectrum light) at the concentrate 154 in the microcavity 136, and detecting at least one of a transmittance and an absorbance of at least a portion of the concentrate 154 in the microcavity 136.

In some embodiments, the microcavity 136 can include a base 146 formed from at least a portion of the second side (or second major surface) 141 of the sample detection container 102, and the base is substantially transparent such that the contents of the microcavity 136 can be seen from the second side 141 of the sample detection container 102 (i.e., from the outside of the sample detection system 100). In such embodiments, any sidewall of the microcavity 136 can be substantially opaque, thereby preventing cross-talk between the apertures and enhancing the effectiveness of detection (particularly optical detection or resolution).

In some embodiments, at least a portion of the sample detection vessel 102 can include a substantially transparent optical window. The optical window may be at least partially coextensive with (i.e., overlap) the microcavity 136 such that the microcavity 136 (and its contents) may be visible from the outside of the sample detection container 102, particularly from the second side 141 of the sample detection container 102.

Alternatively, as shown in step 150E of fig. 4, the sample detection container 102 (i.e., the sample detection system 100) can be inverted, for example, prior to detection, such that the supernatant 156 and centrate 157 resulting from the centrifugation step decant from the microcavity 136, while the concentrate 154 remains in the microcavity 136. As indicated by the large arrow of diagram step 150E, the concentrate 154 in the microcavity 136 can then be resolved (e.g., optically resolved) from outside or exterior to the sample detection container 102 (i.e., from the second side 141 of the sample detection container 102, as indicated by the large arrow). The large arrow is shown pointing vertically downward toward the microcavity 136 (i.e., toward its base 146), but it should be understood that the microcavity 136 may be resolved from any desired direction. As described above, the sample detection container 102, or at least a portion thereof, can be substantially transparent so as to enable the concentrate 154 to be resolved (e.g., optically resolved) from the second side 141. Additionally, in such embodiments, as shown in step 150D of fig. 4, the supernatant 156 (and the separation liquid 157) may be used as a humidity reservoir to avoid substantial evaporation of the concentrate 154 prior to completion of the detection/desorption process.

As further shown in step 150E, because the separation liquid 157 is thicker than the supernatant 156, the separation liquid 157 moves toward the top cover 104 when the sample detection system 100 is inverted.

The term "inverted" is used hereinAnd (2) is used to refer to changing the orientation and may include orienting at various angles and is not limited to changing the orientation 180 degrees. The microcavity 136 can be adapted to assert a standard value of 9.8 m/under normal gravitational forces (e.g., under standard gravitational forces, i.e., earth gravitational acceleration at sea level)²) The concentrate 154 is retained.

In some embodiments, the inverting step can include inverting the container 108 at least 20 degrees (e.g., from-10 degrees to +10 degrees, or from 0 degrees to +20 degrees, etc.), in some embodiments, at least 45 degrees, in some embodiments, at least 60 degrees, in some embodiments, at least 90 degrees, and in some embodiments, 180 degrees. For example, in embodiments where the top cover 104 is oriented at-90 degrees (e.g., relative to horizontal), as shown in steps 150A and 150B of fig. 4, it may be desirable to invert the container 108 at least 90 degrees (e.g., to 0 degrees) or more in order to sufficiently drain the supernatant 156 from the concentrate 154 retained in the microcavity 136 (if such draining is desired).

As described above, the speed of inverting the sample detection container of the present disclosure need not be strictly controlled for the purpose of ensuring that the concentrate 154 is substantially contained in the microcavity 136 and/or avoiding turbulence when the supernatant 156 is drained.

Fig. 5 shows a schematic close-up cross-sectional view of the sample detection vessel 102, wherein the concentrate 154 remains in the microcavity 136 of the sample detection vessel 102. As shown in fig. 5, a microcavity 136 may be formed in the interior surface 124 (or first side 140) of the sample detection container 102.

In some embodiments, as shown in fig. 5, the concentrate 154 may comprise an insoluble material 158 and a liquid 160, which may also comprise a soluble material, particularly a soluble material having a density lower than the insoluble material 158. The concentrate 154, and in particular the insoluble material 158, if present, can comprise an analyte of interest (e.g., a microorganism of interest or an analyte representative of a microorganism of interest), if present in the sample 152. The liquid 160 may comprise at least a portion of the supernatant 156 of the sample 152.

As shown in fig. 5, the separation liquid 157 can separate the concentrate 154 in the microcavity 136 from a substantial portion of the supernatant 156 (see fig. 4) above the microcavity 136, such that the separation liquid 157 covers the top opening 144 of the microcavity 136 and separates the concentrate 154 in the microcavity 136 from the remainder of the sample 152 (e.g., the substantial portion of the supernatant located above or outside the microcavity 136).

The sample detection method 150 shown in fig. 4 and described above can provide for efficient collection and separation of a concentrate 154 of a sample 152 (i.e., any analyte of interest that may be present in the sample 152) with minimal loss of the sample 152 and/or the concentrate 154. For example, efficient collection can be achieved by substantially "trapping" the concentrate 154 (containing the analyte of interest, if present) in the sample detection container 102 during the centrifugation step 150B shown in fig. 4. The concentration of the concentrate 154 may generally be much higher than the sample 152 of any analyte of interest that may be present in the sample 152.

Based on the centrifugation parameters employed in the centrifugation step and/or the number, shape, and size of the microcavities 136 employed in the sample detection container 102, the mass and/or volume of the concentrate 154 remaining in the sample detection container 102 can be determined. That is, the sample detection vessel 102 (and/or the centrifugation step) can be configured to concentrate the desired analyte of interest in accordance with the sample 152. In some embodiments, since the volume of the microcavity 136 of the sample detection container 102 is constant, the sample detection container 102 can be used each time to obtain a predicted volume. The microcavity 136 of the sample detection container 102 will now be described in more detail.

As further shown in fig. 5, a microcavity 136 may be formed in the interior surface 124 of the sample detection container 102. In some embodiments, the one or more microcavities 136 can be formed by a variety of methods, including a variety of microreplication methods, including but not limited to molding (e.g., injection molding), other suitable techniques, or a combination thereof. In some embodiments, the tool (e.g., mold) used to make the microcavities 136 can be formed by a variety of methods, including but not limited to coating, casting, etching (e.g., chemical etching, mechanical etching, reactive ion etching, and the like, and combinations thereof), ablation (e.g., laser ablation, and the like), photolithography, stereolithography, micromachining, knurling (e.g., shear or acid-enhanced knurling), scoring, cutting, and the like, or combinations thereof.

The microcavity 136 is adapted to retain the concentrate 154 resulting from the centrifugation step 150B, fig. 4 and described above.

In the embodiment shown in FIG. 5, the microcavity 136 is shaped to include edges or corners (e.g., at its base 146). Such edges or corners may facilitate retention of the concentrate 154 in the microcavity 136 and may prevent the concentrate 154 from being dislodged from the microcavity 136 under normal gravitational forces. For example, in embodiments where the concentrate 154 has a high surface energy or where the concentrate 154 comprises molecules that are attracted to the material comprising the interior surface 124 of the sample detection vessel 102, the concentrate 154 may be preferentially attracted to the edges and/or corners of the microcavity 136 (i.e., where the concentrate 154 may remain in contact with two or more surfaces), rather than a smooth single surface.

Fig. 5 also shows the effective angle a of the wall 138. As noted above, the effective angle α of the wall 138 of the sample detection container 102 of fig. 1-3, 4, and 5 is shown by way of example as 60 degrees. Further, a single microcavity 136 is shown by way of example only.

As further shown in fig. 5, the separation liquid 157 may separate a concentrate 154 of the sample 152 in the microcavity 136 such that the retained volume is about equal to (or less than) the volume defined by the microcavity 136.

That is, in the systems and methods of the present disclosure employing the separation liquid 157, the ratio of the total retention volume of the concentrate 154 to the microcavity volume is about 1.

Fig. 6 and 7 illustrate a sample detection system 200 according to another embodiment of the present disclosure, where like numerals represent like elements. The sample detection system 200 of fig. 6 and 7 shares many of the same elements, features and functions as the sample detection system 100 described above in connection with fig. 1-5. Reference is made to the description of fig. 1-5 above to more fully illustrate the features and elements (and alternatives to such features and elements) of the embodiment shown in fig. 6-7. Any of the features described above in connection with fig. 1-5 may be applied to the embodiments of fig. 6-7, and vice versa.

The sample detection system 200 includes a sample detection container 202 and a top cover 204. As shown in fig. 6 and 7, the sample detection container 202 may be an elongated tube having a closed end or base 212 (e.g., a tapered closed end 212) and an open end 214. By way of example only, the cap 204 is shown to include a portion (e.g., a protrusion) 213 that is sized to be received in an open end 214 of the sample detection container 202. The cap 204 is further shown to include a tab or flange 215 to facilitate removal of the cap 204 from the sample detection vessel 202 when desired. By way of example only, the sample detection container 202 and the cap 204 are configured to be coupled together by a snap-fit type of fitting. In some embodiments, one or both of the sample detection container 202 and the cap 204 can include a seal (e.g., an O-ring) coupled thereto or integrally formed therewith to provide a sealed container when the sample detection container 202 and the cap 204 are coupled together.

The closed end 212 of the sample detection container 202 may include (i.e., terminate at) one or more micro-cavities 236 adapted to retain sample concentrate to be analyzed, the micro-cavities 236 opening toward the open end 214 of the sample detection container 202. Closed end 212 may also include a wall 238 that extends to microcavity 236 and is oriented at an effective angle α (i.e., relative to longitudinal axis a'). Closed end 212 may also include one or more projections 243 surrounding microcavity 236.

The primary differences between the sample detection system 200 of fig. 6 and 7 and the sample detection system 100 of fig. 1-5 are the overall size/volume and aspect ratio (i.e., the ratio of the length to the transverse dimension (e.g., diameter or width)) of the sample detection vessels 102, 202. The aspect ratio of the specimen detection container 102 is less than the aspect ratio of the specimen detection container 202.

Further, the sample detection container 102 has a transverse dimension (e.g., diameter) that is greater than the diameter of the sample detection container 202. Thus, if microcavity 136 is the same or of the same order of magnitude as microcavity 236, then the ratio of the transverse dimensions (e.g., diameter) of microcavity 136 to sample detection container 102 is less than the ratio of the transverse dimensions (e.g., diameter) of microcavity 236 to sample detection container 202.

By way of example only, the effective angle α of the sample detection vessel 202 is 60 degrees. The sample detection vessels configured as shown in fig. 1-3, 4 and 5, 6-7, and similar sample detection vessels having an effective angle of 45 degrees (see examples) were tested and the results of the tests show that a portion of the sample was effectively retained after centrifugation when using the separation fluids of the present disclosure.

Fig. 8 and 9 illustrate a sample detection system 400 according to another embodiment of the present disclosure, where like numerals represent like elements. The sample detection system 400 of fig. 8 and 9 shares many of the same elements, features, and functions as the sample detection system 100 described above in connection with fig. 1-5 and the sample detection system 200 of fig. 6 and 7. Reference is made to the description of fig. 1-7 above to more fully illustrate the features and elements (and alternatives to such features and elements) of the embodiment shown in fig. 8-9. Any of the features described above in connection with fig. 1-7 may be applied to the embodiments of fig. 8-9, and vice versa.

The sample detection system 400 includes a sample detection container 402. The top cover of the system 400 is not shown in fig. 8, but it should be understood that any of a variety of mating top covers may be used to effectively close and seal the sample detection container 402, such as the top cover 104 of the sample detection system 100. Sample detection container 402 can be coupled to any such cap using any of the above-described coupling devices, optionally with one or more seals (e.g., O-rings).

As shown in fig. 8, the sample detection container 402 may be an elongated tube having a closed end or base 412 (e.g., a non-tapered closed end 412) and an open end 414. The closed end 412 of the sample detection container 402 may include (i.e., terminate at) one or more micro-cavities 436 adapted to retain sample concentrate to be analyzed, the micro-cavities 436 opening toward the open end 414 of the sample detection container 402. By way of example only, sample detection container 402 is shown to include a flat interior surface 424 in which microcavity surfaces are formed such that sample detection container 402 includes a plurality of microcavities 436. Any of the features, alternatives, and methods of making the microcavities 136 described above may also be applied to each of the plurality of microcavities 436 of fig. 8 and 9.

Specifically, the microcavity 436 is formed in a first side 440 of the sample detection container 402 that generally faces the interior (or "inside") of the sample detection container 402 and generally includes the interior surface 424 of the sample detection container 402, or a portion thereof. Specifically, first side 440 may include inner surface 424, in which micro-cavities 436 may be formed such that top opening 444 of each micro-cavity 436 opens toward first side 440 of sample detection container 402 and toward the interior of sample detection container 402 (see fig. 9). The sample detection container 402 may also include a second side 441 generally opposite the first side 440. The second side 441 may face the outside of the sample detection container 402, e.g., away from the sample detection container 402. Thus, the concentrate remaining in the sample detection container 402 (i.e., in the microcavity 436) can be resolved from the second side 441.

The sample detection container configured as shown in fig. 8-9 (see examples) was tested and the results of the testing indicated that a portion of the sample was effectively retained after centrifugation when using the separation fluid of the present disclosure.

By way of example only, fig. 9 shows a close-up schematic of sample detection vessel 402 after sample detection vessel 402 has been subjected to steps 150A through 150D of fig. 4 using separation liquid 157.

As shown in fig. 9, the separation liquid 157 can separate the concentrate 454 in the microcavities 436 from a majority of the supernatant (i.e., located above the microcavities 436 and outside the view of fig. 9) such that the separation liquid 157 covers the top openings 444 of each microcavity 436 and separates the concentrate 454 in each microcavity 436 from the remainder of the sample 452 (e.g., the majority of the supernatant located above or outside the microcavities 436).

In some embodiments, as shown in fig. 9, the concentrate 454 can include an insoluble material 458 and a liquid 460, which can also include a soluble material, particularly a soluble material having a density lower than the insoluble material 458. The concentrate 454, and in particular the insoluble material 458 (if present), can include an analyte of interest (e.g., a microorganism of interest or an analyte representative of a microorganism of interest) (if present in the sample). The liquid 460 may comprise at least a portion of the supernatant of the sample.

As further shown in fig. 9, the separation liquid 157 may separate the sample concentrate 454 in the microcavities 436 such that the retained volume is approximately equal to (or less than) the collection volume defined by the plurality of microcavities 436. That is, in the systems and methods of the present disclosure employing the separation liquid 157, the ratio of the total retention volume of the concentrate 454 to the microcavity collection volume is about 1. Further, for each individual microcavity 436, the ratio of the total retention volume of the concentrate 454 retained in each microcavity 436 to the individual microcavity volume is about 1.

As described above in connection with fig. 8, a microcavity 436 can be formed in the interior surface 424 of the sample detection container 402. However, in some embodiments, alternatively or additionally, microcavity 436 can be formed in a substrate (or liner or film) that can be coupled to (e.g., positioned against) at least a portion of inner surface 424 of sample detection vessel 402. In embodiments employing a substrate (or film), the substrate may have a thickness of at least about 25 microns, in some embodiments, at least about 100 microns, and in some embodiments, at least about 400 microns. In some embodiments, the substrate may have a thickness of no greater than about 2000 microns, in some embodiments, no greater than about 1000 microns, and in some embodiments, no greater than about 250 microns.

In some embodiments, the substrate may be a film that may be formed from a variety of suitable materials including, but not limited to, polyolefins (e.g., polypropylene, polyethylene, or blends thereof), olefin copolymers (e.g., copolymers with vinyl acetate), polyesters (e.g., polyethylene terephthalate and polybutylene terephthalate), polyamides (nylon-6 and nylon-6, 6), polyurethanes, polybutylene, polylactic acid, polyvinyl alcohol, polyphenylene sulfide, polysulfone, polycarbonate, polystyrene, liquid crystal polymers, ethylene-vinyl acetate copolymers, polyacrylonitrile, cyclic polyolefins, or combinations thereof. In some embodiments, the membrane may comprise a compound selected from the group consisting of: l- (3-methyl-n-butylamino) -9, 10-anthracenedione, 1- (3-methyl-2-butylamino) -9, 10-anthracenedione, 1- (2-heptylamino) -9, 10-anthracenedione, 1,3, 3-tetramethylbutyl-9, 10-anthracenedione, 1, 10-decamethylene-bis- (-1-amino-9, 10-anthracenedione), 1-dimethylethylamino-9, 10-anthracenedione and l- (n-butoxypropylamino) -9, 10-anthracenedione. In some embodiments, the film material may comprise a cured polymer. Such cured polymers may be derived from resins selected from the group consisting of: acrylate resins, acrylic-based resins derived from epoxides, polyesters, polyethers, and polyurethanes; an ethylenically unsaturated compound; aminoplast derivatives having at least one pendant acrylate group; polyurethanes (polyureas) derived from isocyanates and polyols (or polyamines); an isocyanate derivative having at least one pendant acrylate group; an epoxy resin other than an acrylated epoxy; and mixtures and combinations thereof.

As further shown in fig. 9, the microcavities 436 may be at least partially defined by a plurality of walls 442, and each microcavity 436 may be further defined by a base 446. In some embodiments, the walls 442 may be intersecting walls 442 defining individual lumens, rather than channels having a length.

In some embodiments, one or more microcavities 436 can define a microcavity surface (or microstructured surface) 439. By way of example only, microcavity surface 439 is shown in fig. 8 as extending across the entire bottom surface of sample detection container 402, however, in some embodiments microcavity surface 439 may only be present in a portion of the base of sample detection container 400.

In such embodiments, the microcavity surface 439 can be formed by a variety of methods, including a variety of microreplication methods, including but not limited to casting, coating, molding, and/or lamination techniques, other suitable techniques, or a combination thereof. For example, the microstructuring of the microcavity surface 439 can be formed by at least one of the following methods: (1) casting a molten thermoplastic using a tool having a microstructured pattern, (2) applying a fluid to the tool having the microstructured pattern, allowing the fluid to solidify, removing the resulting film, and/or (3) passing the thermoplastic film through a nip roll to press against (i.e., imprint) the tool having the microstructured pattern (e.g., a convex mold). The tool may be formed using any of a variety of techniques known to those skilled in the art, the selection of which depends in part on the tool material and the desired topographical features. Other suitable techniques include etching (e.g., chemical etching, mechanical etching, reactive ion etching, and the like, and combinations thereof), ablation (e.g., laser ablation, and the like), lithography, stereolithography, micromachining, knurling (e.g., cutting or acid-strengthened knurling), scoring, cutting, and the like, or combinations thereof.

Alternative methods of forming the microcavity surface 439 include thermoplastic extrusion, curable fluid coating, and embossing thermoplastic layers (which may also be cured). Additional information regarding the substrate or film material and the various processes for forming the microcavity surface 439 can be found, for example, in PCT publication No. wo 2007/070310 and U.S. publication No. us 2007/0134784 to Halverson et al; U.S. publication No. US 2003/0235677 to Hanschen et al; PCT publication No. WO2004/000569 to Graham et al; U.S. Pat. Nos. 6,386,699 to YLAlo et al; U.S. publication No. US 2002/0128578 and U.S. patent nos. US 6,420,622, US 6,867,342 and US 7,223,364 to Johnston et al, each of which is incorporated herein by reference.

By microreplication, the microcavity surfaces 439 can be produced on a large scale without the use of relatively complex processing techniques, with no significant variation between the resulting products. In some embodiments, microcavity surfaces can be prepared by microreplication that retain individual feature fidelity during and after fabrication, and the variation between products is no more than about 50 microns. In some embodiments, microcavity surfaces 439 retain individual feature fidelity during and after fabrication, with no more than 25 microns of variation between products. In some embodiments, microcavity surface 439 comprises a topography (i.e., surface features of the objects, locations, or regions thereof) having an individual feature fidelity that is maintained at a resolution of between about 50 microns and 0.05 microns, and in some embodiments, between about 25 microns and 1 micron.

The microcavities 436 are adapted to retain the concentrate 454 resulting from the centrifugation step 150B of fig. 4. Each microcavity 436 shown in fig. 9 has a generally rectangular cross-sectional shape and is formed by at least two walls 442 and a base or closed end 446, and each microcavity 436 is separated from adjacent microcavities 436 by a wall 442. Each microcavity 436 also includes an open end or top opening 444. It should be understood that the microcavity 436 can include a variety of shapes to enable retention of the concentrate 154. In other words, each microcavity 436 can be shaped and sized to provide a receptacle or aperture for the concentrate 454.

Further, the microcavities 436 shown in FIG. 9 are shown by way of example only as being regularly arranged (e.g., in a grid array). However, it should be understood that the microcavities 436 may include a variety of regular arrangements or arrays, irregular arrangements, or combinations thereof. In some embodiments, microcavities 436 are arranged irregularly, locally or to a lesser extent, but the irregular arrangement is repeating or ordered over a greater extent. Alternatively, in some embodiments, the microcavities 436 are ordered over a smaller range, but the ordered regions are irregularly arranged over a larger range.

Further, in the embodiment shown in FIG. 4, all of the walls 442 are of the same size and shape. However, it should be understood that the wall may have a variety of other shapes. For example, the cross-sectional shape of the wall 442 need not be substantially rectangular, but may include any of the cross-sectional shapes described above.

The walls 442 and the microcavities 436 can be characterized by a variety of sizes, dimensions, distances between the walls 442 or the microcavities 436, relative sizes, and the like. The walls 442 generally have dimensions such as thickness, height, length, width, and the like. Microcavity 436 generally has a volume with dimensions such as radius, diameter, height, width, length, and the like. Generally, the walls 442 and/or the micro-cavity 436 are sized, shaped, and spaced to retain the concentrate 454 in the micro-cavity 436 (e.g., by capillary force) when the sample detection container 402 is in any orientation.

In some embodiments, the average thickness of the walls 442 may be at least about 1 micron, in some embodiments, at least about 5 microns, and in some embodiments, at least about 10 microns. In some embodiments, the average thickness of the walls 442 may be no greater than about 50 microns, in some embodiments, no greater than about 30 microns, and in some embodiments, no greater than about 20 microns.

In some embodiments, the shape and/or size of the walls 442 may be designed to minimize the area of the top surface of the walls 442 so that any material collected on the top surface of the walls 142 may be transferred into the adjacent microcavities 436. For example, in some embodiments, the wall 442 may include a taper toward the top surface. In some embodiments, the top surface may comprise a convex shape. In some embodiments, a combination of tapered and convex shapes may be employed. In some embodiments, the top surface is not arcuate, but rather flat; however, the top surface of the opening 444 defining the microcavity 436 is smooth with no or few sharp edges.

In some embodiments, the configuration of the walls 442 and microcavities 436 in any given region can be selected such that the average pitch P of the walls or microcavities (i.e., the center-to-center distance between adjacent walls 442 or microcavities 436, respectively) is at least about 1 micrometer; in some embodiments, at least about 10 microns; and in some embodiments, at least about 50 microns. In some embodiments, the average pitch P of the walls or microcavities is no greater than about 1000 micrometers, in some embodiments no greater than about 800 micrometers, in some embodiments no greater than about 600 micrometers, in some embodiments no greater than about 500 micrometers, in some embodiments no greater than about 200 micrometers, in some embodiments no greater than about 150 micrometers, and in some embodiments no greater than about 100 micrometers. In some embodiments, pitch P may be in a range of 50 microns to 850 microns.

Generally, the higher the bulk density of the microcavities 436 (e.g., expressed in terms of an average microcavity density or average hole density), the more concentrate 454 can be contained on the first side 440 of the sample detection container 402 within a given area in general. Additionally, in some embodiments, if the microcavity surface 439 includes more land areas (land areas) between the microcavities 436, it is possible that denser portions of the sample (e.g., containing the analyte of interest) can be centrifuged onto the land areas. Thus, in general, a higher density of microcavities on the microcavity surface 439 is preferred for higher trapping potential.

In some embodiments, the average microcavity density is at least about 20 microcavities/cm²And in some embodiments, at least about 30 microcavities/cm²In some embodiments, at least about 70 microcavities/cm²In some embodimentsAt least about 100 microcavities/cm²And in some embodiments, at least about 150 microcavities/cm²And in some embodiments, at least about 200 microcavities/cm²In some embodiments, at least about 500 microcavities/cm²And, in some embodiments, at least about 800 microcavities/cm²And in some embodiments, at least about 900 microcavities/cm²In some embodiments, at least about 1000 microcavities/cm²And in some embodiments, at least about 2000 microcavities/cm²And in some embodiments, at least about 3000 microcavities/cm². In some embodiments, the microcavity density can be about 825 microcavities/cm²。

In some embodiments, the average height of the walls 442 or the average depth of the microcavities 436 (i.e., the distance between the closed end or base 446 of each microcavity 436 and the open end or top opening 444 of the microcavity 436) is at least about 5 micrometers, in some embodiments, at least about 20 micrometers, and in some embodiments, at least about 30 micrometers. In some embodiments, the average height of the walls 442 or the average depth of the microcavities 436 can be no greater than about 1000 micrometers, in some embodiments, no greater than about 250 micrometers, in some embodiments, no greater than about 100 micrometers, and in some embodiments, no greater than about 50 micrometers. In the embodiment shown in fig. 9, the wall height is substantially the same as the microcavity depth; however, it should be understood that this is not necessarily the case. For example, in some embodiments, the microcavity 436 includes a portion that is recessed even below the bottom of the wall 442, such that the depth of the microcavity is greater than the height of the wall. However, even in these embodiments, the above size ranges may be applicable.

As described above, in some embodiments, the microcavities 436 can each include a draft angle β. However, for simplicity, microcavity 436 of fig. 9 does not show such draft angle β.

Fig. 10-14, in which like numerals generally represent like elements, illustrate a sample detection system 300 according to one embodiment of the present disclosure. The sample detection system 300 of fig. 10-14 shares many of the same elements, features and functions as the sample detection systems 100, 200 and 400 described above in connection with fig. 1-5, 6-7 and 8-9, respectively. To more fully describe the features and elements (and alternatives to such features and elements) of the embodiment shown in fig. 10-14, reference is made to the description of fig. 1-9 above. Any of the features described above in connection with fig. 1-5, 6-7, or 8-9 may be applied to the embodiments of fig. 10-14, and vice versa.

The sample detection system 300 illustrates how the sample detection container 102 of fig. 1-3, 4, and 5 (or the sample detection container 202 of fig. 6-7) may be used with a filter assembly that may be used to pre-filter a sample prior to concentrating the sample using the sample detection container 102. The sample detection container 102 is shown by way of example only, but it should be understood that any sample detection container of the present disclosure may alternatively be used in the sample detection system 300.

The sample detection system 300 may include a first container (or "first container assembly") 303 (see fig. 10, 11, and 14) and a second container (or "second container assembly") 305 (see fig. 3, 4, and 5). The second container 305 may comprise the sample detection container 102. In some embodiments, the sample detection system 300 can be used to concentrate a sample to form a concentrate (e.g., located in the microcavity 136, as described below), and can also be used to resolve whether an analyte of interest is present in the concentrate, i.e., to detect the presence or absence of an analyte of interest.

As shown in fig. 10, 11, and 14, first container 303 may include a receiver portion (or "first portion") 306 adapted to hold a sample (e.g., a bulk aqueous sample) and a filter portion (or "second portion") 308 including a filter 312 that may be configured to retain an analyte of interest (if present) in the sample. Filter portion 308 and receiver portion 306 may be configured to be removably coupled together to form first container 303.

As shown in fig. 12-14, the second container 305 can include a filter portion 308 (i.e., a sample filter portion 308) and a sample detection container 102, which sample detection container 102 can also be referred to as a "detection portion" or "third portion". Thus, the filter portion 308 is between the first container 303 and the second containerAny of the devices 305 may be used. As described above, the sample detection container 102 may include a microcavity 136 adapted to receive the sample concentrate when the second container 305 is exposed to centrifugal force, and further adapted to receive the sample concentrate at normal gravitational forces (e.g., a standard value for the acceleration of gravity of the earth at standard gravitational force, i.e., sea level, 9.8 m/s)²) At least a portion of the sample concentrate is retained.

Generally, the first container 303 may be used to filter the sample by passing it through the filter portion 308, and in particular through the filter 312, to form a filtrate and filtrate of the sample. The filter portion 308 may then be detached from the receiver portion 306 of the first container 303 and coupled to the sample detection container 102 to form a second container 305. The second vessel 305 can then be centrifuged toward the microcavity 136 to move at least a portion of the filtrate from the filter 312 to the microcavity 136. In doing so, a precipitate and supernatant of the sample may be formed. The supernatant may be separated from the microcavity 136 using, for example, a separation liquid, and the concentrate may be retained in the microcavity 136. The concentrate may comprise a precipitate that may contain one or more analytes of interest (if present in the sample).

An exemplary sample detection method of the present disclosure will be described in more detail below with reference to fig. 14. The sample detection system 300 will now be described in more detail.

First container 303, and more particularly receiver portion 306, can be adapted to contain a sample to be analyzed (e.g., one or more analytes of interest). The size and shape of the first container 303 (or receiver portion 306) may be designed as desired to accommodate the sample to be analyzed, and the shape and configuration of the receiver portion 306 and filter portion 308 are shown by way of example only.

The receiver portion 306 and the filter portion 308 can be formed from a variety of materials, including but not limited to the materials described above in connection with the sample detection container 102 and the top cover 104 of fig. 1-3, 4, and 5. The receiver portion 306, the filter portion 308, and the sample detection container 102 may be formed of the same or different materials.

The receiver portion 306 may include a first end 314 at least partially defining a reservoir 318, and a second end 316 configured to be coupled (i.e., directly or indirectly) to the filter portion 308. The first end 314 may be an open end or a closed end. By way of example only, in fig. 10 and 11, the first end 314 is closed and the second end 316 is open such that sample may be added to the reservoir 318 through the second end 316 prior to coupling, such as coupling, the receiver portion 306 to the filter portion 308. However, in some embodiments, the first end 314 may be open to allow sample to be added to the reservoir 318 through the first end 314, and the first end 314 may remain open or may be closed with a cover or lid.

As shown in fig. 10, first container 303 may also include a filter connection assembly 320 for coupling filter portion 308 and receiver portion 306 together. In some embodiments, the filter connection assembly 320 may be coupled (e.g., removably or permanently) to the receiver portion 306, and in some embodiments, the filter connection assembly 320 may be integrally formed with the receiver portion 306. By way of example only, filter connection assembly 320 is shown in fig. 10 and 11 as being adapted to couple between receiver portion 306 and filter portion 308.

As shown in fig. 10, in some embodiments, the filter connection assembly 320 may include a connector 322 and a gasket 324. Gasket 324 may be configured to be coupled between connector 322 and receiver portion 306. In some embodiments, as shown, the gasket 324 may be sized to be received in the second end 316 of the receiver portion 306, and the gasket 324 may further include a hole or aperture 326, the hole or aperture 326 sized to receive the first end 323 of the connector 322. For example, the aperture 326 may be shaped and sized to receive the connecting tube 321 of the connector 322. Such a configuration may facilitate forming a seal (e.g., a liquid-tight seal, a gas-tight seal, or a combination thereof) between receiver portion 306 and filter portion 308, thereby sealing the interior of first container 303 from the environment while maintaining fluid communication between receiver portion 306 and filter portion 308 through apertures 326 formed therein. The shape and configuration of the washer 324, the connector 322, and the second end 316 of the receiver portion 306 are shown by way of example only; it should be understood, however, that these elements may take any shape, configuration, and relative configuration to achieve the same function.

As described above, connector 322 may include a first end 323 configured to couple to receiver portion 306 and a second end 325 configured to couple to filter portion 308. By way of example only, second end 325 is shown to include threads 327 that are substantially the same as threads or tracks 123 on sample detection container 102 described above and shown in fig. 1 and 2. Threads 327 on the connector 322 mate with and engage protrusions 329 (see fig. 12) of the filter portion 308 to allow the filter portion 308 to be screwed onto the filter attachment assembly 320 for coupling the filter attachment assembly 320 and the receiver portion 306. By way of example only (as shown in fig. 12), the filter portion 308 (and in particular the filter housing 332) may include a protrusion 329 that is substantially identical to the protrusion 121 on the top cover 104 of the sample detection system 100. In some embodiments, the receiver portion 306 or the filter portion 308 itself may include all of the features of the filter connection assembly 320. Alternatively, in some embodiments, the receiver portion 306 and the filter portion 308 can be configured to be directly coupled to each other.

The threaded connection between the filter portion 308 and the receiver portion 306 (or between the filter portion 308 and the sample detection container 102) is shown by way of example only; however, in some embodiments, manufacturability is enhanced by employing a friction fit (e.g., press fit) or snap fit type coupling arrangement between these components.

As shown in fig. 10 and 11, the filter connection assembly 320 (e.g., connector 322) may also include a vent 328 and a filter plug 330 that serve as air inlets during filtration, particularly in embodiments where the first end 314 of the receiver portion 306 is in a closed state. The filter plug 330 may be used to filter inlet air as it enters the first container 303 during the filtration process. In some embodiments, filter plug 330 may be formed from a hydrophobic material (e.g., polypropylene, polyethylene, Polytetrafluoroethylene (PTFE), or combinations thereof) to prevent sample leakage out of vent 328 and contaminants from entering vent 328.

The filter portion 308 may include a filter housing 332 configured to receive and retain the filter 312. By way of example only, as shown in fig. 12, the filter 312 may be positioned against an upper surface 331 of the filter housing 332. As further shown in fig. 12, the upper surface 331 of the filter housing 332 can include or at least partially define a plurality of apertures 337 (see fig. 10 and 11) in fluid communication with the outlet 339. Such an outlet 339 may serve as an outlet for first receptacle 303 and/or filter portion 308, and may be coupled to a suction source (not shown) to perform a filtration step to move the sample through receiver portion 306, filter connection assembly 320 (if employed), and filter portion 308.

In some embodiments, the filter 312 (e.g., the perimeter thereof) may be ultrasonically welded to the filter housing 332 (e.g., a flange or flange within the housing 332 upon which the perimeter of the filter 312 will sit). Such ultrasonic welding may provide a hermetic seal and additionally provide a method for coupling the filter 312 to the filter housing 332. In still other embodiments, the filter 312 may be integrally formed with the filter housing 332, or sandwiched between two mating components.

Filter portion 308 (or filter housing 332) may include a first end 344 including filter 312 and outlet 339, and a second end 345 configured to be (e.g., removably) coupled to receiver portion 306 (i.e., directly or indirectly, as by filter connection assembly 320) and sample detection container 102, as described below. For example, as shown in fig. 12, in some embodiments, second end 345 may include threads 329 for coupling with threads 327 of filter connection assembly 320 (or receiver portion 306 if filter connection assembly 320 is not employed) and threads 123 of sample detection container 102. Further, by way of example only, in some embodiments, the second end 345 may be sized to receive the second end 325 of the filter connection assembly 320 (or vice versa). Alternatively, if the filter connection assembly 320 is not employed, the second end 345 may be configured to be directly coupled to the receiver portion 306.

Further, as shown in fig. 10 and 12, in some embodiments, a gasket (e.g., an O-ring) 335 may be employed between the filter housing 332 (i.e., between the filters 312) and the filter connection assembly 320 (or the receiver portion 306 if the filter connection assembly 320 is not employed) and/or between the filter housing 332 (i.e., between the filters 312) and the sample detection container 102. Such gaskets 335 may enhance the seal between the receiver portion 306 (e.g., or the filter connection assembly 320) and the filter portion 308. By way of example only, the same gasket 335 has been shown employed in the first container 303 (fig. 10) and the second container 305 (fig. 12); however, this need not necessarily be the case.

As described above, the filter 312 may be configured to retain the analyte of interest (if present) in the sample. The filter 312 may be configured in size, charge, affinity, or other suitable manner to retain the analyte of interest. Any of the filters or membranes described above may be used in the present disclosure.

In particular, the example filter 312 may be fabricated by, for example, a TIPS (thermally induced phase separation) process, a SIPS (solvent induced phase separation) process, a VIPS (vapor induced phase separation) process, a stretching process, track etching, or electrospinning (e.g., PAN fiber membranes). Suitable membrane materials include, for example, polyolefins (e.g., polyethylene and/or polypropylene), ethylene chlorotrifluoroethylene copolymer, polyacrylonitrile, polycarbonate, polyester, polyamide, polysulfone, polyethersulfone, polyvinylidene fluoride (PVDF), cellulose ester, and/or combinations thereof.

Suitable membranes can be characterized as porous membranes or nanofiber membranes. The nanofibrous filtration membrane may have a fibre diameter of less than 5 μm, for example less than 1 μm. The nanofiber membrane may be made from, for example, polyacrylonitrile, polyvinylidene fluoride, cellulose esters, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, and/or combinations thereof.

Certain TIPS polyolefin membranes can be prepared such that they have a single uniform region of membrane structure, each region having a different pore microstructure. In other cases, TIPS films may be prepared as multi-zone films comprising two or more zones, each zone having a different pore microstructure. The multi-region TIPS membrane may include different regions, or may have a transition region between two different regions. Such multi-zone filters may be particularly suitable for use in the systems and methods of the present disclosure due to their ability to elute efficiently. In embodiments employing such multi-zone filters, the side of the filter that includes the smallest pore region may be used as the first side 313.

Exemplary filtration membranes include membranes such as those described in U.S. Pat. No.4,539,256, U.S. Pat. No.4,726,989, U.S. Pat. No.4,867,881, U.S. Pat. No.5,120,594, U.S. Pat. No.5,260,360, international patent publication No. WO2010/078234, international patent publication No. WO2010/071764, PCT publication WO2011/152967, and PCT publication WO 2011/153085.

The filter 312 may include a first side 313 facing the receiver portion 306 during the filtration step and facing the sample detection container 102 (and particularly the microcavity 136) during the centrifugation step, and a second side 315 facing the outlet 339. During filtration, the sample is separated into filtrate 351 (see fig. 13 and 14) and filtrate that remain on the first side 313 of the filter 312. The filtrate may be discarded, as described above, or may be re-passed through the sample processing procedure in an attempt to obtain additional analyte of interest, or otherwise processed.

While the filtrate 351 may be described as remaining on the first side 313 of the filter 312, this does not necessarily mean that the filtrate 351 is not present in any depth of the filter 312 (as may be the case with a porous polymeric membrane having a widely distributed pore size). Conversely, this means that the sample is filtered through the filter 312 from the first side 313 to the second (opposite) side, and the first side 313 is the side of the filter 312 that faces the receiver portion 306 during filtration and the sample detection container 102 during centrifugation. It is possible that at least some of the filtrate may be present below the surface of the first side 313 of the filter 312, i.e., at least partially into the depth of the filter 312. However, certain filters or certain types of filters (e.g., multi-zone filters, homogeneous filters) may be employed to prevent the sample from moving too deep into the filter 312, as moving too deep would require a significant amount of time and elution work to retrieve the filtrate 351 from the filter 312.

As shown in fig. 14, the second end 345 of the filter portion 308 (e.g., the filter housing 332) and the second end 325 of the filter connection assembly 320 (or the second end 316 of the receiver portion 306) may be coupled together and oriented in a first orientation (e.g., upward). The sample 352 may be added to the reservoir 318 of the receiver portion 306, the outlet 339 of the filter portion 308 may be coupled to a suction source, and the sample 352 may be in the first direction D₁Filtering is performed towards the filter 312, the filtrate of the sample 352 flows out of the filter portion 308, while the filtrate 351 of the sample 352 remains on the first side 313 of the filter 312.

In some embodiments, the receiver portion 306 and the filter portion 308, or portions thereof, may be substantially transparent, non-transparent (i.e., substantially opaque), or intervening (e.g., translucent), and may have any suitable size, depending on the type, quantity, and/or size of the sample to be analyzed and the type, quantity, and/or size of the concentrate to be collected and resolved.

The second container 305 will now be described in conjunction with fig. 12-14. As described above, the second container 305 may include the filter portion 308 and the sample detection container 102. The sample detection container 102 may include a microcavity 136.

First end 112 of sample detection container 102 includes microcavity 136, and second end 114 is configured to be coupled to second end 345 of filter section 308. As shown in fig. 12, in some embodiments, second end 114 of sample detection container 102 can be sized to be received in filter portion 308 (i.e., filter housing 332), and threads 123 can be configured to mate with and engage protrusions 329 of filter portion 308 in the same manner that threads 123 mate with and engage protrusions 121 of top cap 104 of sample detection system 100 in fig. 1-3, 4, and 5. Such engagement may allow sample detection container 102 and filter portion 308 to be threaded together, and in particular, removably coupled together. However, in some embodiments, filter portion 308 and sample detection container 102 can be removably coupled together by other means (e.g., any of the above-described means). In some embodiments, the entire second container 305 may be disposable and may be discarded after the detection process. However, it should be understood that in some embodiments, the sample detection container 102 may instead be sized to receive at least a portion of the filter housing 308.

By way of example only, the sample detection container 102 is shown as a larger portion of the second container 305, such that the sample detection container 102 acts as a tube or reservoir for the second container 305 and the filter portion 308 acts as a top cover or lid for the second container 305. However, it should be understood that the size, shape, and relative dimensions of the components of the second container 305 may be adjusted to suit a particular sample or situation.

The first side 140 (see fig. 2, 3, and 13) of the sample detection container 102 generally faces the interior of the second container 305, and the second side 141 of the sample detection container 102 generally faces the exterior of the second container 305. Thus, the second side 141 will also generally face away from the filter portion 308. Thus, the concentrate remaining in the sample detection container 102 can be resolved from the second side 141, such as in embodiments where at least a portion (e.g., the first (closed) end 112 and/or the second side 141) of the sample detection container 102 is substantially transparent. In some embodiments, at least a portion of the microcavity 136 (e.g., a base 146 thereof) can be substantially transparent in order to view, detect, and/or resolve the contents of the microcavity 136 from the second side 141.

As shown in fig. 12 and 13, in some embodiments, the outlet 339 of the filter portion 308 for removing filtrate in a filtration step and performing a first sample concentration step can be sealed or closed, for example, by a cap 317. For example, the cap 317 can be coupled to the outlet 339 after the filtering step, and particularly coupled to the outlet when the filter portion 308 is coupled with the sample detection receptacle 102 to form the second receptacle 305.

In some embodiments, the initial sample volume (i.e., the volume of the sample prior to any concentration steps (including filtration and/or centrifugation)) of the analyte of interest to be detected may be at least about 5 mL; in some embodiments, at least about 10 mL; in some embodiments, at least about 25 mL; in some embodiments, at least about 50 mL; in some embodiments, at least about 100 mL; in some embodiments, at least about 500 mL; in some embodiments, at least about 1L; in some embodiments, at least about 2L; in some embodiments, at least about 5L; and in some embodiments, at least about 10L.

In some embodiments, the volume of the sample detection container 102 or the second container 305 may range from about 1mL to about 250 mL. Thus, in some embodiments, the volume of the sample (e.g., the sample formed from the filtrate 351 of the initial sample 352 and the one or more diluents added after filtration) may be at least about 1 mL; in some embodiments, at least about 10 mL; and in some embodiments, at least about 100 mL. In some embodiments, the volume of the sample is no greater than about 200 mL; in some embodiments, no greater than about 100 mL; in some embodiments, no greater than about 75 mL; and, in some embodiments, no greater than about 50 mL. In some embodiments, the volume of the sample ranges from about 1mL to about 100 mL.

In some embodiments, the ratio of the volume of the sample detection container 102 or the second container 305 to the volume of sample concentrate (or retentate) retained in the sample detection container 102 is at least 100:1 (10)²1); in some embodiments, at least about 1000:1 (10)³1); in some embodiments, at least about 10,000:1 (10)⁴1), and in some embodiments, at least about 100,000:1 (10)⁵1); in some embodiments, at least about 10⁸1, preparing a catalyst; in some embodiments, at least about 10⁹1, preparing a catalyst; in some embodiments, at least about 10¹⁰1, preparing a catalyst; and in some embodiments, at least about 10¹¹:1. In some embodiments, the ratio of the volume of the sample detection container 102 or the second container 305 to the volume of concentrate retained in the sample detection container 102 is from about 100:1 to about 10¹¹1 in the range of.

As with figures 1 to 3, 4 and 5The sample detection system 100, in some embodiments, the concentration increase (i.e., the concentration of the resulting concentrate (e.g., the concentration of the denser material, such as the analyte of interest) retained in the sample detection vessel 102 divided by the concentration of the initial sample (either before or after filtration), expressed as a ratio) can be at least about 100:1 (10)²1); in some embodiments, at least about 1000:1 (10)³1); in some embodiments, at least about 10,000:1 (10)⁴1), and in some embodiments, at least about 100,000:1 (10)⁵:1). In some embodiments, the concentration efficiency is from about 10:1 to about 10⁵1 in the range of.

In some embodiments, the receiver portion 306 of fig. 10 and 11 may have a capacity of at least about 1mL, at least about 5mL, at least about 10mL, at least about 25mL, at least about 50mL, at least about 100mL, or at least about 250 mL. That is, in some embodiments, the capacity or volume of the receiver portion 306 may be in the range of about 1mL to about 250mL, and in some embodiments, may be in the range of about 1mL to about 100 mL. In some embodiments, the filter portion 308, the sample detection container 102, and/or the second container 305 can have a capacity of no greater than about 1mL, no greater than about 2mL, no greater than about 5mL, or no greater than about 10 mL.

The shape, size, and manner of coupling of receiver portion 306, filter portion 308, and sample detection container 102 are described above and shown by way of example only in fig. 10-14. However, it should be understood that the receiver portion 306, filter portion 308, and sample detection container 102 may take on a variety of shapes and sizes. In addition, receiver portion 306 and filter portion 308, and filter portion 308 and sample detection container 102 may be removably and/or permanently coupled together using a variety of coupling means, including but not limited to threads (as shown in the figures); clamps (e.g., spring-loaded clamps, snap-type clamps, etc.); clips (e.g., spring-loaded clips, etc.); a tie (e.g., a cable tie); one or more magnets; an adhesive tape; a binder; an adhesive; hook and loop fasteners; a snap-fit joint (e.g., where the filter housing 308 acts as a flip-top); compression fittings (sometimes referred to as "friction fit fittings" or "interference fit fittings"); thermal bonding (e.g., heat and/or pressure applied to one or both components to be coupled); welding (e.g., sonic (e.g., ultrasonic) welding); other suitable coupling means; and combinations thereof.

Referring to fig. 14, a sample detection method 350 will now be described, at which point reference will continue to be made to the sample detection system 300 of fig. 10-13, with the microcavity 136 schematically shown for purposes of illustration.

The first step (i.e., the filtration step) of the sample detection method 350 is described above in connection with the first container 303. The filtration step may sometimes be referred to as a first concentration step of the sample detection method 350 and the subsequent centrifugation step may sometimes be referred to as a second concentration step, such that the sample detection method 350 may be described as comprising two concentration steps to obtain a sample concentrate from which an analyte of interest may be resolved.

The filtrate 351 of the sample 352 trapped on the first side 313 of the filter 312 can then be retrieved from the filter 312 using a variety of means including, but not limited to, elution, agitation, washing, other suitable means for retrieving the filtrate 351 from the filter 312, or a combination thereof. For example, in some embodiments, retrieving filtrate 351 may include adding one or more diluents (e.g., an elution solution and/or a wash solution) to filter portion 308 (or second container 305). The elution solution can be configured to elute filtrate 351 from filter 312, such as by disrupting any affinity between filtrate 351 and filter 312. In some embodiments, after adding one or more diluents to the filter portion 308, the sample detection vessel 102 can be coupled to the filter portion 308 to form the second vessel 305, and the second vessel 305 can be agitated to help remove the filtrate 351 in the filter 312. A new "sample" 352' may thus be formed, comprising filtrate 351 and any diluent added.

In particular, in the embodiment shown in fig. 10-14, in forming the second container 305, the second (open) end 114 of the sample detection container 102 can be inserted into the second (open) end 345 of the filter portion 308, and the protrusion 329 (see fig. 12) of the filter portion 308 and the threads 123 of the sample detection container 102 can be threaded together.

As shown in the third step of fig. 14, the second container 305 may then be inverted to a second orientation and in a second direction (or orientation) D toward the sample detection container 102₂Centrifugation (see the fourth step of FIG. 14). This centrifugation process can cause the concentrate 354 containing the denser material in the initial sample 352 (and the filtered sample 352') to migrate into the sample detection vessel 102, and more specifically into the microcavity 136 formed in the sample detection vessel 102. The "concentrate" 354 may generally include a precipitate of the sample 352, 352 'formed by the centrifugation process, but may also include at least some supernatant or diluent of the sample 352, 352', as described above. The centrifugation step shown in the fourth step of fig. 14 may generally be performed after the centrifugation step 150B of fig. 4 described above.

As shown in the fifth step of fig. 14, one or more separation liquids 357 may then be added to the sample detection container 102. For example, filter portion 308 can be temporarily removed from sample detection vessel 102 to add separation liquid 357, and then second vessel 305 can be re-closed by coupling filter portion 308 to sample detection vessel 102.

As shown in the fifth step of fig. 14, the separation liquid 357 effectively displaces the supernatant 356 from the microcavity 136 outside of the microcavity 136, such that the concentrate 354 of the samples 352, 352' is retained in the microcavity 136. That is, the separation liquid 357 moves between the concentrate 354 located in the microcavity 136 and the sample remainder in the sample detection container 102, such that the separation liquid 357 effectively separates the concentrate 354 contained in the microcavity 136 from the majority of the supernatant 356.

As further shown in fig. 14 (i.e., by two optional sixth steps in the method 350), the concentrate 354 in the microcavity 136 can then be resolved (e.g., by optical resolution), or inverted prior to resolution. The resolution is indicated by large arrows in the last two optional steps of fig. 14. As shown in the first optional resolution step, the supernatant 356 and the separation liquid 357 may remain above (i.e., cover the top opening of) the microcavity 136 during resolution.

As shown in the second optional resolution step, the sample detection container 102 (i.e., the second container 305) can be inverted, for example, prior to detection, such that the supernatant 356 and the centrate 357 resulting from the centrifugation step are decanted from the microcavity 136, while the concentrate 354 remains in the microcavity 136. The inversion step shown in the second optional sixth step of fig. 14 may generally be performed after the inversion step 150E of fig. 4 described above.

As described above, sample detection container 102, or at least a portion thereof, can be substantially transparent, and separation liquid 357 can be colorless, so as to be able to resolve (e.g., optically resolve) concentrate 354 from any desired orientation. The two optional parsing (or detection) steps of fig. 14 may generally be performed after the two optional parsing steps 150D and 150E of fig. 4 described above.

As further shown in the second optional resolution step, because the separation liquid 357 is denser than the supernatant 356, the separation liquid 357 moves toward the filter portion 308 when the second container 305 is inverted.

In some embodiments, particularly when the second container 305 is inverted, the supernatant 356 may be removed from the second container 305 and discarded, or used in a subsequent processing step (e.g., repeated centrifugation steps).

The sample detection method 350 illustrated in fig. 14 and described above, respectively, can provide for efficient collection and separation of the concentrate 354 of the sample 352, 352' (i.e., any analyte of interest that may be present in the sample 352, 352 '), with minimal loss of the sample 352, 352' and/or the concentrate 354. For example, efficient collection can be achieved by substantially "trapping" the concentrate 354 (containing the analyte of interest (if present)) in the sample detection container 102 during the centrifugation step shown in the fourth step of fig. 14, and subsequently adding the separation liquid 357. The concentration of the analyte of interest in the concentrate 354 is typically much higher than the concentration of any analyte of interest in the sample 352, 352 'that may be present in the sample 352, 352'.

The embodiments described above and illustrated in the drawings are provided by way of example only and are not intended as a limitation upon the concepts and principles of the present disclosure. As such, it will be appreciated by one having ordinary skill in the art that various changes in the elements and their configuration and arrangement are possible without departing from the spirit and scope of the present disclosure.

All references and publications cited herein are expressly incorporated by reference in their entirety into this disclosure.

The following embodiments are intended to be illustrative of the present disclosure and not limiting.