阅读说明：本技术 生物素-亲和素或链霉亲和素的无微球均相化学发光体系 (Microsphere-free homogeneous chemiluminescence system of biotin-avidin or streptavidin ) 是由 奚伟红 于 2019-11-22 设计创作，主要内容包括：本发明公开了生物素-亲和素或链霉亲和素的无微球均相化学发光体系,以及将其用于定量测量抗原或抗体的方法,涉及化学发光体系技术领域,所述的无微球均相化学发光体系包括：生物素标记的抗体或抗原、9,10-二氢吖啶标定的抗体或抗原、HRP标记的亲和素或链霉亲和素。生物素-亲和素或生物素-链霉亲和素的无微球均相化学发光(No Microspheres Honogeneous Luminescent(Biotin-Avidin/streptavidin))体系不使用微球,是均相体系；引入生物素-亲和素/链霉亲和素系统,可以大大提高化学发光效率,提高检测灵敏度,实例S100B蛋白最低检测浓度可达到0.015ng/ml；该体系检测过程不需清洗,方便简单,可用于自动免疫均相化学发光系统,POCT及微流控芯片等快速定量分析。(The invention discloses a microsphere-free homogeneous chemiluminescence system of biotin-avidin or streptavidin, and a method for quantitatively measuring an antigen or an antibody by using the same, and relates to the technical field of chemiluminescence systems, wherein the microsphere-free homogeneous chemiluminescence system comprises the following components in parts by weight: biotin-labeled antibody or antigen, 9, 10-dihydroacridine-labeled antibody or antigen, HRP-labeled avidin or streptavidin. A microsphere-free homogeneous chemiluminescence (No Microspheres Honnogeneous luminescences (Biotin-Avidin/streptavidin)) system of Biotin-Avidin or Biotin-streptavidin does not use Microspheres and is a homogeneous system; the biotin-avidin/streptavidin system is introduced, so that the chemiluminescence efficiency can be greatly improved, the detection sensitivity is improved, and the minimum detection concentration of the protein of example S100B can reach 0.015 ng/ml; the system has the advantages of no need of cleaning in the detection process, convenience and simplicity, and can be used for rapid quantitative analysis of an automatic immune homogeneous chemiluminescence system, a POCT (point of care testing) chip, a microfluidic chip and the like.)

1. A microsphere-free homogeneous chemiluminescence system based on biotin-avidin or biotin-streptavidin is characterized in that: the method comprises the following steps: biotin-labeled antibody or antigen, 9, 10-dihydroacridine-labeled antibody or antigen, HRP-labeled avidin or streptavidin.

2. The microsphere-free homogeneous chemiluminescent system of claim 1 wherein: the steps for preparing the HRP-labeled avidin or streptavidin are as follows: adding 60mmol/L NaIO40.1ml into 1mg HRP, acting at 4 deg.C for 30min, adding 0.1ml ethylene glycol with concentration of 0.16mol/L, after 30min, adding 1mg A or SA, standing at 4 deg.C for 24 hr; dialyzing overnight, adding an equal volume of saturated ammonium sulfate solution, centrifuging at 4000r/min for 15 minutes, dissolving the precipitate in PBS, measuring the absorbance at 280nm and scanning at the wavelength of 200-280 nm; loading 100ul of HRP-SA or HRP-A on Sephadex G-75 column, eluting with 0.025mol/L KCL-0.2mol/L acetic acid buffer solution at 0.5ml/2min, and collecting fractions; measuring and collecting OD280 value of each tube sample by using a DU800 ultraviolet spectrophotometer, drawing an elution curve, collecting a single white peak, and concentrating dialysate by using PEG-2000; 1 HRP-SA or HRP-A and 100ul deionized double distilled water are taken and scanned by an ultraviolet spectrophotometer at the wavelength of 200 and 280nm until the HRP-SA has an absorption peak at 280 nm.

3. The microsphere-free homogeneous chemiluminescent system of claim 2 wherein: the pH of the PBS was 7.4.

4. The microsphere-free homogeneous chemiluminescent system of claim 1 wherein: the steps for preparing the biotin-labeled antibody or antigen are as follows: diluting an antigen or an antibody to be labeled by biotin to 1-2.5ml by using a buffer solution to prepare an antigen or antibody solution, wherein the buffer solution is 0.1mol/L sodium bicarbonate buffer solution or 0.5mol/L boric acid buffer solution; dissolving 1mg of NHSB in 1ml of DMS0 to obtain NHSB solution; adding 120u1NHSB solution into 1ml antigen or antibody solution, stirring at room temperature, keeping the temperature for 2-4 hours, adding 9.6 μ L NH4CL with the concentration of 1mol/L, and stirring for 10 minutes; dialyzing the PBS at 4 ℃ to remove free biotin; passing the sample through a 1ml molecular sieve column, eluting slowly with PBS, collecting 1 ml/tube, and washing antigen or antibody between 1-3m 1; adding 50% volume of redistilled glycerol into the eluate, and storing at 20 deg.C.

5. The microsphere-free homogeneous chemiluminescent system of claim 4 wherein: the pH value of the sodium bicarbonate buffer solution is 8.0.

6. The microsphere-free homogeneous chemiluminescent system of claim 5 wherein: the pH value of the boric acid buffer solution is 8.6.

7. The method for quantitative measurement of antigen or antibody by microsphere-free homogeneous chemiluminescence system of claims 1-6, wherein: the method comprises the following steps: s1, reagent preparation: respectively preparing a calibrator, an auxiliary agent and a trigger, and preparing a biotin-labeled antibody or antigen, a 9, 10-dihydroacridine-labeled antibody or antigen, and HRP-labeled avidin or streptavidin; s2, sample adding: adding a biotin-labeled antibody or antigen, a 9, 10-dihydroacridine-labeled antibody or antigen, and HRP-labeled avidin or streptavidin into a calibrator or a sample, and oscillating and uniformly mixing to prepare a mixture A to be detected; s3, detection: adding an auxiliary agent into the mixture A to be detected, shaking and mixing uniformly, standing, adding a trigger, shaking and mixing uniformly to prepare a mixture B to be detected, detecting, and reading a luminous value; s4, calculating: and (4) performing logistic four-parameter fitting on the concentration and the luminescence value of the calibrator, and calculating the concentration of the sample through the sample RLU.

8. The method of claim 7, wherein: the volume of the calibrator, the sample, the enzyme label, the biotin label and the luminescent label described in step S2 was 25 uL.

9. The method of claim 7, wherein: the addition volumes of the adjuvant and the trigger described in step S3 were 5uL and 75uL, respectively.

10. The method of claim 7, wherein: the standing time described in step S3 is 1-2 minutes.

Technical Field

The invention relates to the technical field of chemiluminescence systems, in particular to a biotin-avidin or streptavidin microsphere-free homogeneous chemiluminescence system and a method for quantitatively measuring an antigen or an antibody by using the same.

Background

The LOCI (luminescent oxygen channeling immunological) diagnostic technique was discovered in the early 90 s by the American scientist, professor Ullman, and was developed by Delin, USA. The technology is based on that two nano microspheres excite the formed chemiluminescence reaction of adjacent sites by utilizing the short-distance diffusion of singlet oxygen energy to determine the interaction between biomolecules, and is a non-radioactive detection and analysis method.

The LOCI system needs two different microspheres, photosensitizer phthalocyanine dye, a dimethylthiophene derivative and a rare earth chelate need to be filled in the microspheres respectively, the uniformity of the microspheres in different batches and quantitative filling in the microspheres need harsh production processes and equipment, and meanwhile, the system using the microspheres is not a real homogeneous phase, and the heterogeneous phase can influence the repeatability of a detection result.

The Biotin-Avidin System (BAS) is a new type of amplification System for biological reactions developed in the late 70 s. The strong binding with high affinity between biotin and avidin and the multi-stage amplification effect make BAS immune labeling and related tracing analysis more sensitive. BAS has been widely used in qualitative and quantitative detection and location observation of antigen and antibody.

Biotin (B) is widely distributed in animal and plant tissues, is usually extracted from yolk with high content and liver tissues, has molecular weight of 244.31Da, and has two cyclic structures, wherein ring I is an imidazolone ring and is a main part combined with avidin; the ring II is a thiophene ring, a valeric acid side chain is arranged on C2, the terminal carboxyl group of the valeric acid side chain is the only structure for combining antibodies and other biological macromolecules, and biotin can become a derivative with various active groups, namely activated biotin after chemical modification.

Avidin (AV), also known as avidin and ovalbumin, is a basic glycoprotein extracted from ovalbumin and composed of 4 identical subunits, and has a molecular weight of 68 kD. The 4 identical subunits allow each avidin to bind up to 4 molecules of biotin. Biotin has a very strong affinity for avidin, much higher than the affinity between antigen and antibody. And the combination stability of the two is good and the specificity is strong. The Streptavidin (SA) molecule consists of 4 identical peptide chains, wherein the amino acid composition has high content of glycine and alanine, and an active group combined with biotin is a tryptophan residue in the peptide chain; streptavidin is a slightly acidic protein (ph6.0) and does not carry any sugar groups. Under the action of proteolytic enzyme, streptavidin can be broken between the N end 10-12 and the C end 19-21, and the formed core streptavidin still maintains the complete biotin-binding capacity. The unit of streptavidin activity is expressed in terms of the amount required to bind 1. mu.g of biotin, with 1mg of streptavidin having a maximum activity of up to 18U.

At present, no microsphere-free homogeneous chemiluminescence system based on biotin-avidin or biotin-streptavidin exists, and the microsphere-free homogeneous chemiluminescence system can be used for rapid quantitative analysis of an automatic immunization homogeneous chemiluminescence system, POCT (point of care testing), a microfluidic chip and the like.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a microsphere-free homogeneous chemiluminescence system based on biotin-avidin or biotin-streptavidin, which is characterized in that: the method comprises the following steps: biotin-labeled antibody or antigen, 9, 10-dihydroacridine-labeled antibody or antigen, HRP-labeled avidin or streptavidin.

The steps for preparing the HRP-labeled avidin or streptavidin are as follows: adding 60mmol/L NaIO40.1ml into HRP1mg, acting at 4 deg.C for 30min, adding 0.1ml of 0.16mol/L ethylene glycol, after 30min, adding 1mgA or SA, standing at 4 deg.C for 24 hr; dialyzing overnight, adding an equal volume of saturated ammonium sulfate solution, centrifuging at 4000r/min for 15 minutes, dissolving the precipitate in PBS, measuring the absorbance at 280nm and scanning at the wavelength of 200-280 nm; the column was packed with Sephadex G-75. HRP-SA or HRP-A was loaded to 100ul, eluted with 0.025mol/L KCL-0.2mol/L acetate buffer at 0.5ml/2min and collected in fractions. Measuring and collecting OD280 value of each tube sample by using a DU800 ultraviolet spectrophotometer, drawing an elution curve, collecting a single white peak, and concentrating dialysate by using PEG-2000; 1 HRP-SA or HRP-A and 100ul deionized double distilled water are taken and scanned by an ultraviolet spectrophotometer at the wavelength of 200 and 280nm until the HRP-SA has an absorption peak at 280 nm.

The pH of the PBS was 7.4.

The steps for preparing the biotin-labeled antibody or antigen are as follows: diluting an antigen or an antibody to be labeled by biotin to 1-2.5ml by using a buffer solution to prepare an antigen or antibody solution, wherein the buffer solution is 0.1mol/L sodium bicarbonate buffer solution or 0.5mol/L boric acid buffer solution; dissolving 1mg of NHSB in 1ml of DMS0 to obtain NHSB solution; adding 120u1NHSB solution into 1ml antigen or antibody solution, stirring at room temperature, keeping the temperature for 2-4 hours, adding 9.6 μ L NH4CL with the concentration of 1mol/L, and stirring for 10 minutes; dialyzing the PBS at 4 ℃ to remove free biotin; passing the sample through a 1ml molecular sieve column, eluting slowly with PBS, collecting 1 ml/tube, and washing antigen or antibody between 1-3m 1; adding 50% volume of redistilled glycerol into the eluate, and storing at 20 deg.C.

The pH value of the sodium bicarbonate buffer solution is 8.0.

The pH value of the boric acid buffer solution is 8.6.

A method for quantitatively measuring an antigen or an antibody based on a microsphere-free homogeneous chemiluminescence system of biotin-avidin or biotin-streptavidin comprises the following steps: s1, reagent preparation: respectively preparing a calibrator, an auxiliary agent and a trigger, and preparing a biotin-labeled antibody or antigen, a 9, 10-dihydroacridine-labeled antibody or antigen, and HRP-labeled avidin or streptavidin; s2, sample adding: adding a biotin-labeled antibody or antigen, a 9, 10-dihydroacridine-labeled antibody or antigen, and HRP-labeled avidin or streptavidin into a calibrator or a sample, and oscillating and uniformly mixing to prepare a mixture A to be detected; s3, detection: adding an auxiliary agent into the mixture A to be detected, shaking and mixing uniformly, standing, adding a trigger, shaking and mixing uniformly to prepare a mixture B to be detected, detecting, and reading a luminous value; s4, calculating: and (4) performing logistic four-parameter fitting on the concentration and the luminescence value of the calibrator, and calculating the concentration of the sample through the sample RLU.

The volume of the calibrator, the sample, the biotin-labeled antibody or antigen, the 9, 10-dihydroacridine-labeled antibody or antigen, and the HRP-labeled avidin or streptavidin described in step S2 was 25 uL.

The addition volumes of the adjuvant and the trigger described in step S3 were 5uL and 75uL, respectively.

The standing time described in step S3 is 1-2 minutes.

The steps for preparing the calibrator are as follows:

preparing a calibrator diluent: weighing 14.1g of dipotassium hydrogen phosphate and 2H of sodium dihydrogen phosphate ₂Dissolving O3.0 g in ultrapure water, adding Proclin-3000.5-1 mL, uniformly mixing, adding ultrapure water to a constant volume of 1000mL to obtain a calibrator diluent, and storing at 2-8 ℃ for later use; preparing a calibrator: the concentration of the calibrator is 0, 10ng/mL, 50ng/mL, 500ng/mL, 1000ng/mL and 10000ng/mL, the antigen or antibody calibrator is diluted to a corresponding concentration by using a calibrator diluent, and the calibrator is stored at 2-8 ℃ for later use.

The preparation method of the auxiliary agent comprises the following steps:

weighing 1.82g of citric acid and 10.45g of sodium citrate, adding pure water to dissolve and fix the volume to 1000mL, adding a luminescence auxiliary agent into a citrate buffer solution, mixing uniformly, subpackaging, and storing in a refrigerator at 4 ℃ for later use; among them, 10mL per bottle is more preferable.

The steps for preparing the trigger are as follows:

weighing 6.06g of Tris and 9g of sodium chloride, adding a proper amount of pure water for dissolving, adding 2.1mL of concentrated HCl, and uniformly mixing; adding tween-202 mL, mixing, diluting to 1000mL, packaging, and storing in a refrigerator at 4 deg.C; among them, more preferably 200mL per bottle.

The steps for preparing the 9, 10-dihydroacridine labeled antibody or antigen are as follows:

the luminescent substrate Acridan was dissolved in 500. mu.L of DMF; sucking 41.3 mu L of dissolved Acridan, adding 708.7 mu L of 0.05M sodium borate buffer solution, adding 250 mu L of antigen or antibody, turning and uniformly mixing for 4-5 times, and standing for 30min at room temperature; and (3) placing the marked reaction tube on a shaking table, mixing at 2-8 ℃ overnight, taking out, adding a proper amount of glycerol, and storing in a refrigerator at-20 ℃.

The principle of the microsphere-free homogeneous phase chemiluminescence system is that biotin-avidin/streptavidin is introduced into a spatially adjacent homogeneous phase chemiluminescence system, biotin is marked on one antibody molecule, 9, 10-dihydroacridine (Acridan) is marked on the other antibody molecule, and HRP is marked on the avidin/streptavidin molecule. When the antigen in the sample reacts with the antibody marked with biotin and the antibody marked with 9, 10-dihydroacridine (Acridan) respectively to form an antigen-antibody complex, the complex is combined with the avidin/streptavidin marked with HRP to form an antigen-antibody-biotin-avidin/streptavidin complex, so that the antigen-antibody-biotin-avidin/streptavidin complex are close to each other in space, and after a trigger auxiliary agent is added, flash chemiluminescence is generated. In the system, Microspheres are not connected with Biotin or Avidin/streptavidin, but are connected with an antibody by adopting Biotin, and the homogeneous chemiluminescence formed by connecting the Avidin/streptavidin with HRP is adopted, so the system is called a microsphere-free homogeneous chemiluminescence system of Biotin-Avidin or Biotin-streptavidin, namely an NMHL (No Microspheres-Honnogeneous emitting luminescence) system.

Another object of the present invention is to protect the application of the above method in the automated immune homogeneous chemiluminescence system, POCT and rapid quantitative analysis of microfluidic chips.

The invention has the beneficial effects that:

a microsphere-free homogeneous chemiluminescence (No Microsp heres Honogeneous luminescences system (Biotin-Avidin/streptavidin) system does not use microspheres and is a homogeneous system, a Biotin-Avidin/streptavidin system is introduced, the chemiluminescence efficiency can be greatly improved, the detection sensitivity is improved, the minimum detection concentration of the protein in the example S100B can reach 0.015ng/m l, the detection process of the system does not need to be cleaned, and the system is convenient and simple and can be used for rapid quantitative analysis of an automatic immunization homogeneous chemiluminescence system, a POCT (point of care computed tomography), a microfluidic chip and the like.

Drawings

In order to more clearly illustrate the detailed description of the invention or the technical solutions in the prior art, the drawings that are needed in the detailed description of the invention or the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.

FIG. 1 is a calibration log four parameter fit curve of example 1.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.

It is to be noted that, unless otherwise specified, technical or scientific terms used herein shall have the ordinary meaning as understood by those skilled in the art to which the invention pertains.