阅读说明：本技术 一种用于细胞注射的皮升级液体注射装置及注射方法 (Picoliter-grade liquid injection device and injection method for cell injection ) 是由 常博 宋龙刚 周权 于 2020-12-21 设计创作，主要内容包括：本发明属于细胞注射技术领域,具体公开了一种用于细胞注射的皮升级液体注射装置及注射方法,该装置包括细胞注射模块、运动控制模块和显微成像模块；细胞注射模块包括毛细玻璃管、注射针筒、推杆、注射位移台和针筒固定块；运动控制模块包括二维运动平台和三维运动平台,二维运动平台上放置有用于承载待注射细胞的载玻片；注射位移台和注射针筒固定块连接在三维运动平台上,实现毛细玻璃管三维定位；注射针筒上端与推杆连接,下端与毛细玻璃管连接；推杆固定件用于夹持推杆,滑块连接有上位机,通过上位机控制推杆移动达到精确控制皮升级的液体注射。本发明的注射装置注射精度高,结构紧凑简单,成本低。(The invention belongs to the technical field of cell injection, and particularly discloses a picoliter liquid injection device and an injection method for cell injection, wherein the device comprises a cell injection module, a motion control module and a microimaging module; the cell injection module comprises a capillary glass tube, an injection syringe, a push rod, an injection displacement table and a syringe fixing block; the motion control module comprises a two-dimensional motion platform and a three-dimensional motion platform, and a glass slide for bearing cells to be injected is placed on the two-dimensional motion platform; the injection displacement table and the injection needle cylinder fixing block are connected on the three-dimensional motion platform to realize three-dimensional positioning of the capillary glass tube; the upper end of the injection syringe is connected with the push rod, and the lower end of the injection syringe is connected with the capillary glass tube; the push rod fixing piece is used for clamping the push rod, the sliding block is connected with an upper computer, and the push rod is controlled by the upper computer to move so as to achieve liquid injection of accurate control of skin upgrading. The injection device of the invention has the advantages of high injection precision, compact and simple structure and low cost.)

1. A picoliter-grade liquid injection device for cell injection is characterized by comprising a cell injection module, a motion control module and a microimaging module;

the motion control module comprises a two-dimensional motion platform (16) and a three-dimensional motion platform, a slide glass (17) used for bearing cells to be injected is placed on the two-dimensional motion platform (16), and the two-dimensional motion platform (16) is used for driving the slide glass (17) to move in the X direction and the Y direction;

the cell injection module comprises a capillary glass tube (1), an injection syringe (2), a push rod (3), an injection displacement table (5) and a syringe fixing block (6), and the inner diameter of the injection syringe (2) is micron-sized;

the injection displacement table (5) and the syringe fixing block (6) are connected on the three-dimensional motion platform, the syringe fixing block (6) is used for clamping the injection syringe (2), the upper end of the injection syringe (2) is connected with the push rod (3), and the lower end of the injection syringe (2) is connected with the capillary glass tube (1); the three-dimensional motion platform is used for driving the cell injection module to move in a three-coordinate system;

a sliding block (23) and a guide rail (24) are arranged in the injection displacement table (5), the sliding block (23) is installed on the guide rail (24), a push rod fixing piece (4) is fixedly connected to the sliding block (23), the push rod fixing piece (4) is used for clamping a push rod (3), and the sliding block (23) is connected with an upper computer;

the glass slide (17) is arranged below the capillary glass tube (1), and the microscopic imaging module is arranged on one side of the two-dimensional moving platform (16).

2. The picoliter-grade liquid injection device for cell injection according to claim 1, wherein the push rod (3) comprises a needle body (31) and a tail extrusion block (32) connected with the needle body (31), the needle body (31) is used for being inserted into the injection syringe (2), and the diameter of the needle body (31) is micron-grade.

3. The device for injecting liquid into cells according to claim 2, wherein the needle body (31) is a stainless steel needle.

4. The picoliter-grade liquid injection device for cell injection according to claim 1, wherein the capillary glass tube (1) is installed at the lower end of the injection cylinder (2) at the upper part and at the pointed end at the lower part.

5. The pico-liter liquid injection device for cell injection according to claim 1, wherein the syringe fixing block (6) is connected with a syringe fixing member (7), a semi-circular groove is formed on the side of the syringe fixing block (6) opposite to the syringe fixing member (7), and the two semi-circular grooves form a channel for clamping the injection syringe (2).

6. The device of claim 5, wherein the rubber cushion is disposed in the two semicircular grooves.

7. The liquid injection apparatus for cell injection according to claim 1, wherein the push rod fixing member (4) comprises a connecting plate (41) and a holding plate (42), the connecting plate (41) has two bolt holes, the holding plate (42) has a U-shaped slot (45) to form a front baffle and a back baffle;

the front baffle is provided with a V-shaped groove (44), and the rear baffle is provided with a set screw (46).

8. The picoliter-grade liquid injection device for cell injection according to claim 1, wherein the three-dimensional motion platform comprises an X-direction linear displacement stage (10), a Y-direction linear displacement stage (11), and a Z-direction linear displacement stage (12); a first guide rail is arranged in the X-direction linear displacement table (10), a first sliding block is sleeved on the first guide rail, and the Y-direction linear displacement table (11) is fixed on the first sliding block; a second guide rail is arranged in the Y-direction linear displacement table (11), a second sliding block is sleeved on the second guide rail, a connecting block is arranged on the second sliding block, and the Z-direction linear displacement table (12) is connected to the connecting block; a third guide rail is arranged in the Z-direction linear displacement table (12), a third slide block is sleeved on the third guide rail, and the injection displacement table (5) and the needle cylinder fixing block (6) are fixedly connected onto the third slide block.

9. The device for injecting liquid into cells of claim 1, wherein the micro-imaging module comprises a micro-camera (18) and a high power micro-lens (19) which are connected by screw threads, and the micro-camera (18) is fixed on the camera bracket (21) through a camera fixing plate (20).

10. The injection method of the picoliter-grade liquid injection device for cell injection as set forth in any one of claims 1 to 9, comprising the steps of:

s1, sucking the injection liquid into the injection syringe (2), and fixing the injection syringe (2) on the syringe fixing piece (7);

s2, placing a slide (17) carrying the cells to be injected on a two-dimensional motion platform (16);

s3, controlling the two-dimensional motion platform (16) and the three-dimensional motion platform to move until the microscopic imaging module observes that the lower end of the capillary glass tube (1) and the cells to be injected are placed in a visual field range and aligned;

s4, controlling the capillary glass tube (1) to penetrate into the cell to be injected through a three-dimensional motion platform;

s5, setting parameters on the upper computer, controlling the slide block to move through the upper computer, and driving the push rod (3) to move downwards by the slide block to push out the injection liquid in the injection syringe (2).

Technical Field

The invention relates to the technical field of cell injection, in particular to a picoliter liquid injection device and an injection method for cell injection.

Background

Cell injection using a very fine-tipped glass injection needle to inject foreign substances directly into cultured cells or prokaryotic embryos is one of the most commonly used methods for cell or early embryo manipulation. The cell injection method requires a high-precision injection instrument and a high-precision operation device. The traditional cell injection is mainly manually operated by researchers, because of the limit of the level of operating hardware and the different operating capability of the operators, the success rate of the cell injection experiment is low and the repeatability is poor. With the development of bioengineering and the development of cell injection automation, various automatic cell injection instruments and platforms are successively proposed by related research institutions at home and abroad, but the injection precision and the positioning precision still need to be improved, and meanwhile, the instruments are complex in structure and high in price and need to be trained by operators for a long time.

Disclosure of Invention

The invention aims to provide a picoliter liquid injection device and an injection method for cell injection, and solves the problems of low injection precision and complex structure in the field of cell injection at present.

The invention is realized by the following technical scheme:

a picoliter-grade liquid injection device for cell injection comprises a cell injection module, a motion control module and a microimaging module;

the motion control module comprises a two-dimensional motion platform and a three-dimensional motion platform, a slide glass used for bearing cells to be injected is placed on the two-dimensional motion platform, and the two-dimensional motion platform is used for driving the slide glass to move in the X direction and the Y direction;

the cell injection module comprises a capillary glass tube, an injection syringe, a push rod, an injection displacement table and a syringe fixing block, and the inner diameter of the injection syringe is micron-sized;

the injection displacement table and the needle cylinder fixing block are connected to the three-dimensional motion platform, the needle cylinder fixing block is used for clamping an injection needle cylinder, the upper end of the injection needle cylinder is connected with the push rod, and the lower end of the injection needle cylinder is connected with the capillary glass tube; the three-dimensional motion platform is used for driving the cell injection module to move in a three-coordinate system;

a sliding block and a guide rail are arranged in the injection displacement table, the sliding block is arranged on the guide rail, a push rod fixing piece is fixedly connected to the sliding block, the push rod fixing piece is used for clamping a push rod, and the sliding block is connected with an upper computer;

the glass slide is arranged below the capillary glass tube, and the microscopic imaging module is arranged on one side of the two-dimensional motion platform.

Further, the push rod comprises a needle body and a tail extrusion block connected with the needle body, the needle body is used for being inserted into the injection syringe, and the diameter of the needle body is micron-sized.

Furthermore, the needle body adopts a stainless steel needle.

Furthermore, the upper part of the capillary glass tube is arranged at the lower end of the injection syringe, and the lower part of the capillary glass tube is a tip.

Further, the needle cylinder fixing block is connected with a needle cylinder fixing piece, a semicircular groove is formed in one side, opposite to the needle cylinder fixing piece, of the needle cylinder fixing block, and a channel used for clamping the injection needle cylinder is formed by the two semicircular grooves.

Further, the push rod fixing piece comprises a connecting plate and a clamping plate, two bolt holes are formed in the connecting plate, and a U-shaped groove is formed in the clamping plate to form a front baffle and a rear baffle;

the front baffle is provided with a V-shaped groove, and the rear baffle is provided with a set screw.

Further, the three-dimensional motion platform comprises an X-direction linear displacement platform, a Y-direction linear displacement platform and a Z-direction linear displacement platform; a first guide rail is arranged in the X-direction linear displacement table, a first sliding block is sleeved on the first guide rail, and the Y-direction linear displacement table is fixed on the first sliding block; a second guide rail is arranged in the Y-direction linear displacement table, a second sliding block is sleeved on the second guide rail, a connecting block is arranged on the second sliding block, and the Z-direction linear displacement table is connected to the connecting block; a third guide rail is arranged in the Z-direction linear displacement platform, a third slide block is sleeved on the third guide rail, and the injection displacement platform and the needle cylinder fixing block are fixedly connected onto the third slide block.

Furthermore, the microscopic imaging module comprises a microscopic camera and a high power microscope lens which are connected through threads, and the microscopic camera is fixed on the camera bracket through a camera fixing plate.

The invention also discloses an injection method of the picoliter liquid injection device for cell injection, which comprises the following steps:

s1, sucking injection liquid into the injection syringe, and fixing the injection syringe on the syringe fixing piece;

s2, placing a glass slide carrying the cells to be injected on a two-dimensional motion platform;

s3, controlling the two-dimensional motion platform and the three-dimensional motion platform to move until the microscopic imaging module observes that the lower end of the capillary glass tube and the cell to be injected are placed in a visual field range and aligned;

s4, controlling the capillary glass tube to penetrate into the cell to be injected through the three-dimensional motion platform;

and S5, setting parameters on the upper computer, controlling the slide block to move through the upper computer, and driving the push rod to move downwards by the slide block to push out the injection liquid in the injection syringe.

Compared with the prior art, the invention has the following beneficial technical effects:

the invention discloses a picoliter liquid injection device and an injection method for cell injection, wherein the injection device comprises a cell injection module, a microimaging module, a two-dimensional motion platform and a three-dimensional motion platform, a glass slide for bearing cells to be injected is placed on the two-dimensional motion platform, and the microimaging module is used for observing the relative position of a capillary glass tube and the cells; the cell injection module comprises a capillary glass tube, an injection needle cylinder, a push rod, an injection displacement table and a needle cylinder fixing block, the injection displacement table and the needle cylinder fixing block are connected to a three-dimensional motion platform, the cell injection module is driven to move in a three-dimensional coordinate system through the three-dimensional motion platform, and a slide glass is driven to move preliminarily through the two-dimensional motion platform; the injection displacement table is internally provided with a guide rail sliding block mechanism, the sliding block is connected with an upper computer, the upper computer controls the sliding block to move, and the sliding block drives a push rod to move downwards to push out the injection liquid in the injection needle cylinder, so that the pico-liter level liquid injection of the capillary glass tube is realized. The upper computer controls the push rod to realize the nanometer stepping distance, and simultaneously, the micro-scale inner diameter of the needle cylinder is combined to achieve the aim of accurately controlling the liquid injection of skin upgrading. The injection method has high precision, and the injection method has compact and simple structure and low cost.

Furthermore, the injection syringe and the needle body have micron-sized inner diameters with the same size, so that the movement of the push rod in the injection syringe is ensured, and the injection precision and stability are ensured.

Furthermore, the capillary glass tube is formed by drawing a glass capillary, the diameter of the tip can reach 0.1 micron, the diameter of human cells is between 5 and 200 microns, the size of animal cells is between 20 and 30 microns, and the capillary glass tube meets the use requirements of most cell injection.

Drawings

FIG. 1 is a schematic view of the construction of a picoliter-grade liquid injection apparatus for cell injection according to the present invention;

FIG. 2 is a schematic view showing the structure of the junction of a capillary glass tube, an injection cylinder and a push rod of the present invention;

FIG. 3 is a schematic structural view of the putter fixing member of the present invention;

FIG. 4 is a flow chart of a method of injecting picoliter liquid for cell injection according to the present invention.

The device comprises a glass capillary tube 1, an injection needle cylinder 2, a push rod 3, a push rod fixing part 4, an injection displacement table 5, a needle cylinder fixing block 6, a needle cylinder fixing part 7, a needle cylinder fixing plate 8, a fixing screw 9, a linear displacement table in the X direction 10, a linear displacement table in the Y direction 11, a linear displacement table in the Z direction 12, a flat plate connecting block 13, a damping table 14, a right-angle connecting block 15, a two-dimensional motion platform 16, a glass slide 17, a microscope camera 18, a high-magnification microscope lens 19, a camera fixing plate 20, a camera support 21, a right-angle connecting piece 22, a sliding block 23 and a guide rail 24, wherein the glass capillary tube is a hollow glass tube;

31 is a needle body, and 32 is a tail extrusion block;

reference numeral 41 denotes a connecting plate, 42 denotes a holding plate, 43 denotes a screw hole, 44 denotes a V-shaped groove, 45 denotes a U-shaped groove, and 46 denotes a set screw.

Detailed Description

The present invention will now be described in further detail with reference to specific examples, which are intended to be illustrative, but not limiting, of the invention.

As shown in FIG. 1, the present invention discloses a pico-liter liquid injection device for cell injection, which comprises a cell injection module, a motion control module and a micro-imaging module, wherein the cell injection module, the motion control module and the micro-imaging module are integrated on a shock absorption table 14.

The cell injection module comprises a capillary glass tube 1, an injection needle cylinder 2, a push rod 3, a push rod fixing piece 4 and an injection displacement table 5 and is used for realizing accurate micro-injection of the capillary glass tube 1. The capillary glass tube 1 is tightly connected through the mounting hole at the end of the injection syringe 2 and is convenient to replace. The injection syringe 2 is fixed on the syringe fixing plate 8 through the syringe fixing block 6, so that the injection syringe 2 is convenient to mount and dismount.

The needle cylinder fixing block 6 is connected with a needle cylinder fixing piece 7, one side of the needle cylinder fixing block 6, which is opposite to the needle cylinder fixing piece 7, is provided with a semicircular groove, and the two semicircular grooves form a channel for clamping the injection needle cylinder 2. The syringe fixing block 6 is connected with the syringe fixing piece 7 through the manual fixing screw 9, and rubber cushions are arranged in the two semicircular grooves, so that the injection syringe 2 can be protected from being damaged due to overlarge pressure exerted by the manual fixing screw 9, meanwhile, the friction force between the injection syringe 2 and the syringe fixing block 6 and the syringe fixing piece 7 is increased, and the syringe is prevented from moving.

As shown in fig. 2, the push rod 3 is composed of a micrometer diameter needle body 31 and a tail extrusion block 32, and the needle body 31 is a stainless steel needle and is tightly combined with the inner wall of the syringe 2. A trace amount of liquid is injected through the plunger 3 at the stainless needle portion in the syringe 2 to the top of the capillary glass tube 1. The tail part of the push rod 3 is fixed on an injection displacement table 5 through a push rod fixing piece 4. The push rod fixing piece 4 enables the axis of the stainless steel needle to coincide with the axis of the inner cavity of the injection needle cylinder 2.

The injection displacement table 5 is fixed on the needle cylinder fixing plate 8 through screws, the injection displacement table 5 has nanometer precision, and the push rod fixing piece 4 drives the push rod 3 to extrude liquid in the injection needle cylinder 2 to reach the end part of the capillary glass tube 1 to complete cell injection. The nanoscale micro-motion of the injection displacement table 5 is combined with the micron-sized inner diameter of the injection needle cylinder 2, so that the picoliter-level liquid injection of the liquid injection device is realized. Meanwhile, the inner diameter of the injection syringe 2 and the outer diameter of the push rod 3 are reduced, so that the injection device can realize more micro injection control.

Be equipped with slider 23 and guide rail 24 in the injection displacement platform 5, slider 23 installs on guide rail 24, fixedly connected with push rod mounting 4 on the slider, and push rod mounting 4 is used for centre gripping push rod 3, and slider 23 is connected with the host computer through servo motor, can set up parameters such as velocity of motion, minimum step length and movement distance at the host computer, and then control push rod 3's displacement to reach the liquid volume of control injection.

The motion control module comprises a two-dimensional motion platform 16 and a three-dimensional motion platform, a glass slide 17 for containing cells to be injected is placed on the two-dimensional motion platform 16, and the position of the cells to be injected is approximately the same as that of the capillary glass tube 1 by rotating a control knob on the two-dimensional motion platform 16 to move the glass slide 17.

The three-dimensional motion platform comprises three precise electric linear platforms, namely an X-direction linear displacement platform 10, a Y-direction linear displacement platform 11 and a Z-direction linear displacement platform 12, and is used for controlling the three-dimensional motion of the capillary glass tube 1. Wherein the X-direction linear displacement platform 10 is connected with the damping platform 14 through a flat plate connecting block 13, the Y-direction linear displacement platform 11 is installed on the X-direction linear displacement platform 10, the Y-direction linear displacement platform 11 is connected with the Z-direction linear displacement platform 12 through a right-angle connecting block 15, and the needle cylinder fixing plate 8 is fixed on a sliding block of the Z-direction linear displacement platform 12. The precise three-dimensional motion of the tip of the capillary glass tube 1 is realized by driving the needle cylinder fixing plate 8 through three precise electric linear platforms, namely an X-direction linear displacement platform 10, a Y-direction linear displacement platform 11 and a Z-direction linear displacement platform 12. Meanwhile, the Y-direction linear displacement stage 11 and the Z-direction linear displacement stage 12 may also be connected by a connection block having a certain angle, so that the capillary glass tube 1 obtains a certain initial injection angle, and a wider injection function may be accomplished.

Specifically, the X-direction linear displacement table 10 is connected to a flat plate connection block 13 by a bolt, and the flat plate connection block 13 is connected to a damping table 14 by a screw. A first guide rail is arranged in the X-direction linear displacement table 10, a first sliding block is sleeved on the first guide rail, and the Y-direction linear displacement table 11 is fixed on the first sliding block; a second guide rail is arranged in the Y-direction linear displacement table 11, a second sliding block is sleeved on the second guide rail, a connecting block is arranged on the second sliding block, and the Z-direction linear displacement table 12 is connected to the connecting block; a third guide rail is arranged in the Z-direction linear displacement table 12, a third slide block is sleeved on the third guide rail, and the injection displacement table 5 and the needle cylinder fixing block 6 are fixedly connected to the third slide block through a needle cylinder fixing plate 8.

The microscopic imaging module is mainly composed of a microscopic camera 18 and a high power microscope lens 19, and is used for observing the relative positions of the tip of the capillary glass tube 1 and the cells to be injected on the glass slide 17. Wherein the microscope camera 18 is connected with the high power microscope lens 19 through screw threads, the microscope camera 18 is fixed on the camera support 21 through the camera fixing plate 20, and the camera support 21 is fixed on the shock absorption table 14 through the right-angle connecting piece 22. The microscopic imaging function can also be provided by other means such as an inverted biological microscope.

The device realizes the picoliter liquid injection through the nanometer micro-motion of the injection displacement platform 5 and the micron-scale inner diameter of the injection needle cylinder 2. The precise linear platforms in three directions are combined for use, and the nano-scale positioning of the tip of the capillary glass tube 1 is realized. Meanwhile, the device has simple structure and low cost, and can be widely applied to the field of cell injection.

The capillary glass tube 1 is formed by drawing a glass capillary, the diameter of the tip can reach 0.1 micron, the diameter of human cells is between 5 and 200 microns, the size of animal cells is between 20 and 30 microns, and the capillary glass tube 1 meets the use requirements of most cell injection. The capillary glass tube 1 is tightly connected through the mounting hole at the end part of the injection syringe 2, and is convenient to replace.

The injection syringe 2 is made of glass materials, so that the injection resistance of the push rod 3 is effectively reduced, and the injection syringe is beneficial to the uniformity of the injection process. The outer wall of the injection syringe 2 is marked with scale lines, minimum resolution and measuring range, so that the injection volume can be observed through eyes, and the experimental record is convenient. The injection syringe 2 has a micron-sized inner diameter, the size of the inner diameter is the same as the outer diameter of the push rod 3, the movement of the push rod 3 in the injection syringe 2 is ensured, no gap is left, and the injection precision and stability are ensured. Meanwhile, the inner diameter of the injection syringe 2 and the outer diameter of the push rod 3 are reduced, and the device can realize more micro injection control.

The push rod 3 is composed of a micrometer diameter stainless steel needle and a rear pressing block 32, and is tightly combined with the inner wall of the syringe 2. The liquid in the syringe 2 is pressed by the push rod 3 to inject a minute amount of liquid into the cells through the capillary glass tube 1.

The minimum theoretical injection quantity is the product of the cross-sectional area of the inner wall of the injection cylinder 2 and the minimum displacement of the injection displacement table 5. The nanoscale feeding motion of the injection displacement table 5 is combined with the micron-sized inner diameter of the injection needle cylinder 2, so that the picoliter-level liquid injection precision of the liquid injection device is realized.

As shown in fig. 3, the push rod fixing member 4 is formed by processing an aluminum block, and includes a connecting plate 41 and a clamping plate 42, two bolt holes are formed on the connecting plate 41, a U-shaped groove 45 is formed on the clamping plate 42 to form a front baffle and a rear baffle, a V-shaped groove 44 is formed on the front baffle, an arc-shaped supporting surface with the same diameter as the stainless steel needle is arranged at the bottom of the V-shaped groove 44, and the stainless steel needle is mounted on the arc-shaped supporting surface. The tailgate is provided with a manual set screw 46.

The U-shaped groove 45 has a height greater than the tail squeeze block 32 for receiving the tail squeeze block 32. The tail compression block 32 is secured by manually tightening the set screw 46.

Meanwhile, the invention provides a picoliter liquid injection method for cell injection. Wherein, the cell injection method adopts the picoliter-grade liquid injection device for cell injection. As shown in fig. 4, the injection method of picoliter liquid for cell injection provided by the present invention mainly comprises the following steps:

s1, sucking the injection liquid into the injection syringe 2;

s2, mounting the injection syringe 2 on the syringe fixing piece 7;

s3, placing a slide glass 17 carrying the cells to be injected on the two-dimensional motion platform 16;

s4, using a three-dimensional motion platform and the microscope camera 18 to enable the tip of the capillary glass tube 1 and the cell to be injected to be arranged in a visual field range and aligned;

s5, controlling the capillary glass tube 1 to accurately penetrate into the cell to be injected through a three-dimensional motion platform;

s6, setting parameters on the upper computer, controlling the slide block to move through the upper computer, driving the push rod 3 to move downwards by the slide block, pushing out the injection liquid in the injection syringe 2, and performing accurate quantitative injection on the cells to be injected.

After the injection operation is finished, the capillary glass tube 1 is controlled to leave the injected cells through the three-dimensional motion platform, and the glass slide 17 carrying the injected cells is taken down to finish the whole operation process.

Through the steps, the accurate micro cell injection is realized, and the method has guiding significance for cell culture, in-vitro fertilization and early embryo micromanipulation. Meanwhile, the injection method of the cell injection is high in injection precision and the positioning precision of the tip of the capillary glass tube 1, and can be widely applied to the field of cell injection.

The invention combines the micron-sized capillary glass tube 1, the nanometer-sized positioning method and the pico-liter injection method, has simple device structure design, low cost and strong practicability, and can be widely applied to precise and quantitative injection of cells.