CN116814391A - Cell sorter based on filter membrane - Google Patents

Abstract

The invention provides a cell sorter based on a filter membrane, which comprises a stock solution filter liquid path, a sample liquid circulation liquid path, the filter membrane and a filter membrane chip assembly, wherein the filter membrane chip assembly comprises an upper chip and a lower chip, the upper chip is provided with a liquid inlet, a liquid return port and a liquid outlet, a first cell sorting groove, a liquid inlet channel and a liquid return channel are arranged on the lower surface of the upper chip, the liquid inlet channel is connected with the liquid inlet and the first cell sorting groove, a second cell sorting groove, a liquid outlet groove and a liquid outlet channel are arranged on the upper surface of the lower chip, the filter membrane is arranged between the first cell sorting groove and the second cell sorting groove, the liquid outlet channel is connected with the second cell sorting groove and the liquid outlet groove, the liquid return channel is connected with the first cell sorting groove and the liquid return port, and the stock solution filter liquid path is connected with the liquid inlet, the liquid outlet, the sample liquid circulation liquid inlet and the liquid return port.

Description

Cell sorter based on filter membrane

Technical Field

The invention belongs to the technical field of target cell sorting instruments, and particularly relates to a cell sorting instrument based on a filter membrane.

Background

Malignant solid tumor cells can fall off from the primary focus, spread and survive in the circulatory or lymphatic system, and can colonize and grow at a position far away from the primary focus when conditions allow, thereby forming new tumor tissues. These secondary distant metastases occurring in organs such as lung, brain, liver or bones will eventually lead to death of the patient. With the advent of advanced detection instruments and the development of high-sensitivity immunocytochemical detection methods and molecular biological detection methods in recent years, a way is provided for specific detection of these suppressed metastatic tumor cells from the single cell level.

Circulating tumor cells can be detected in the peripheral blood of certain early stage malignant patients, disseminated tumor cells can be detected in regional lymph nodes and bone marrow, and bladder malignant cells can be detected in urine. Since the number of tumor cells in blood and urine is extremely rare, in order to be able to detect these cells, a sensitive and reliable method must be found, in which tumor target cells in a peripheral blood sample or urine sample are first enriched and then identified and analyzed.

Enrichment of tumor target cells is currently mainly based on both physical properties (density and volume) and molecular biological properties (immunomagnetism and infiltration capacity) of tumor target cells. The enrichment method of the tumor target cells comprises the following steps: according to the different cell volumes, the polycarbonate membrane with the aperture of 8 microns is used for filtering a peripheral blood or urine sample, tumor cells with larger volume are left on the membrane, and smaller normal blood and urine cells pass through the filter membrane, so that the tumor cells are enriched on the polycarbonate membrane, namely, the technology of separating the tumor cells by membrane filtration.

The Chinese patent publication No. CN113846012A discloses a centralized cell sorting system and a sorting method, comprising a microfluidic cell sorting device for enriching target cells from a cell suspension sample containing the target cells, and a first driving mechanism for driving the cell suspension sample into the microfluidic cell sorting device; the microfluidic cell sorting device is provided with a pipeline A for flowing out sample waste liquid and a pipeline B for flowing out target cells, and is a deterministic lateral offset microfluidic chip; the deterministic lateral offset microfluidic chip comprises a deterministic lateral offset region; one side of the deterministic lateral offset region comprises an inlet a, and the other side comprises an outlet B; the inlet A comprises at least two channels, one channel is used for inputting the cell suspension sample, and the other channel is used for inputting buffer solution; the outlet B comprises at least two channels; one channel is used for flowing out the target cells and the buffer solution, and the other channel is used for flowing out the sample waste liquid; after all samples to be treated are sorted by the microfluidic cell sorting device, all target cells in the samples to be treated are blocked above the filter membrane by the microporous filter membrane device, a flow path of a pipeline B is switched to be communicated with the second device by a reagent switching valve of the second device, and five reagents are sequentially loaded into the microporous filter membrane device by a reagent sample injection device of the second device according to the planned sequence through the switching of the reagent switching device, so that the treatments of fixing, permeabilizing, sealing, dyeing, cleaning and the like of the cells in the microporous filter membrane device are realized.

The technical scheme has the following defects: because the target cells are trapped above the filter membrane by the microporous filter membrane device, the situation that the reagent is only mixed with the supernatant of the sample, but the target cells are still deposited and adsorbed on the filter membrane often occurs in the processes of fixing, permeabilizing, sealing, staining, cleaning and the like of the cells in the microporous filter membrane device.

Disclosure of Invention

The invention aims to solve the following technical problems: in the prior art, when extracting cells trapped by a filter membrane in a microporous filter membrane device, only cell supernatant can be extracted, and part of target cells cannot be extracted.

The invention provides a cell sorter based on a filter membrane, which can carry out internal circulation on target cells trapped by the filter membrane during sampling, so that the target cells are separated from the filter membrane and uniformly dispersed in a sample liquid.

In order to achieve the above purpose, the invention adopts the following technical scheme:

the utility model provides a cell sorter based on filter membrane, includes stoste filter liquor way, sample liquid circulation liquid way, filter membrane and filter membrane chip subassembly, filter membrane chip subassembly includes chip and lower chip, is equipped with inlet, return liquid mouth, liquid outlet on the last chip, is equipped with first cell sorting groove, inlet channel, return liquid runner on the lower surface of last chip, and the inlet is connected the inlet with cell sorting groove one is equipped with second cell sorting groove, play cistern, outlet channel on the upper surface of lower chip, and first cell sorting groove corresponds with second cell sorting groove each other, and outlet correspond each other, and the filter membrane sets up between first cell sorting groove and second cell sorting groove, and the outlet channel is connected the second cell sorting groove with the outlet, the return liquid runner is connected first cell sorting groove with the return liquid mouth, the stoste filter liquor way includes first peristaltic pump, first peristaltic pump is connected the inlet, the liquid outlet is connected first peristaltic pump, sample liquid circulation liquid way includes second peristaltic pump and second peristaltic pump, the sample liquid is connected to the second peristaltic pump is connected to the sample liquid receiver.

Further, a first auxiliary runner is arranged on the periphery of the first cell sorting groove on the upper chip, the first auxiliary runner is arc-shaped, a plurality of first branch runners connected with the first auxiliary runner and the first cell sorting groove are arranged between the first auxiliary runner and the first cell sorting groove, and the plurality of first branch runners are arranged in a radial mode.

Further, a second auxiliary runner is arranged on the periphery of the second cell sorting groove on the lower chip, the second auxiliary runner is arc-shaped, a plurality of second branch runners connected with the second auxiliary runner and the second cell sorting groove are arranged between the second auxiliary runner and the second cell sorting groove, the plurality of second branch runners are arranged in a radial mode, and the second auxiliary runner is arranged on one side, away from the liquid outlet runner, of the second cell sorting groove.

Further, the filter membrane is in a shape of a circular sheet, the diameter of the filter membrane is 8 mm, the thickness of the filter membrane is 100 microns, tens of thousands of filter holes are uniformly distributed on the filter membrane, and the aperture of each filter hole is 8 microns.

Further, a circle of silica gel ring is fixedly connected with the outer edge of the filter membrane.

Further, magnets are arranged at four corners of the upper chip and the lower chip, and the upper chip and the lower chip are mutually attracted through the magnets.

Further, the upper surface of the upper chip is integrally provided with liquid path connectors which are in one-to-one correspondence with the liquid inlet, the liquid return port and the liquid outlet.

Further, cell sorter still includes the chip mounting bracket, the chip mounting bracket includes roof, bottom plate, a plurality of chip seat, a plurality of jacking cylinder, the roof with bottom plate fixed connection, be equipped with the opening on the roof, a plurality of jacking cylinders are installed the bottom of bottom plate, every jacking cylinder's piston rod passes the bottom plate and with corresponding chip seat fixed connection, be equipped with on the chip seat and be used for placing filter membrane chip assembly's chip standing groove.

After the technical scheme is adopted, the invention has the following advantages:

1. the invention relates to a cell sorter based on a filter membrane, which comprises the following raw liquid filter liquid paths: the stock solution flows in from the liquid inlet of the upper chip and flows to the first cell sorting groove through the liquid inlet channel; under the action of gravity, the stock solution in the first cell sorting tank enters the second cell sorting tank through the filter membrane, and target cells to be sorted are trapped on the upper surface of the filter membrane; the waste liquid entering the second cell sorting groove passes through the liquid outlet channel of the lower chip, enters the liquid outlet groove, flows out through the liquid outlet of the upper chip, and finally is discharged from the cell sorter. The flow direction of the sample liquid circulation liquid path is as follows: the sample liquid flows in from the liquid inlet of the upper chip, flows to the first cell sorting groove through the liquid inlet channel, takes away target cells trapped on the upper surface of the filter membrane, flows out from the liquid return port of the upper chip through the liquid return channel of the upper chip, flows in from the liquid inlet of the upper chip again, and is circulated repeatedly.

The cell sorter based on the filter membrane can carry out internal circulation on target cells trapped by the filter membrane during sampling, so that the target cells are separated from the filter membrane and uniformly dispersed in a sample liquid.

2. The invention relates to a cell sorter based on a filter membrane, wherein a first auxiliary flow channel and a first branch flow channel are arranged on an upper chip. When the raw liquid flows into the first cell sorting tank, the raw liquid firstly enters the first auxiliary flow channel and then enters the middle part of the first cell sorting tank through a plurality of first branch flow channels, and the flowing mode ensures that the raw liquid is distributed on the filter membrane more uniformly, so that the effective contact area of the raw liquid and the filter membrane is increased; when the sample liquid flows into the first cell sorting groove, the sample liquid firstly enters the first auxiliary flow channel, and then enters the middle part of the first cell sorting groove through a plurality of first branch flow channels, so that inward impulsive force is generated to strip target cells on the filter membrane.

3. The invention relates to a cell sorter based on a filter membrane, wherein a second auxiliary flow channel and a second branch flow channel are arranged on a lower chip. When the waste liquid flows out of the second cell sorting groove, the waste liquid is guided to the middle part of the second cell sorting groove from the second auxiliary flow channel through a plurality of second branch flow channels and then is intensively guided out of the second cell sorting groove through the liquid outlet flow channel, and the enrichment of the waste liquid in the second cell sorting groove is avoided by the flowing mode, so that the waste liquid can be rapidly discharged along with the diversion.

4. According to the cell sorter based on the filter membrane, the upper chip and the lower chip which are arranged in a split mode are adopted, so that the disposable filter membrane can be quickly installed and detached. And because the upper chip and the lower chip are mutually attracted through the magnet, the filter membrane can be conveniently taken down from the lower chip by separating the upper chip and the lower chip, and after a new filter membrane is placed, the filter membrane is fixed by the attraction of the upper chip and the lower chip.

Drawings

FIG. 1 is a schematic diagram of a filter-based cell sorter;

FIG. 2 is a schematic diagram of a filter-based cell sorter with the cover omitted;

FIG. 3 is a schematic diagram of a filter membrane chip assembly;

FIG. 4 is a schematic diagram of the structure of the upper chip;

FIG. 5 is a schematic diagram of the structure of the lower chip;

FIG. 6 is a schematic diagram of a filter membrane structure;

FIG. 7 is a schematic diagram of a liquid path connection structure of a filter membrane chip assembly;

FIG. 8 is a schematic view of the mounting structure of a first peristaltic pump and a second peristaltic pump;

FIG. 9 is a schematic structural view of a chip mount;

in the figure:

1-a filter membrane;

2-mounting a chip;

3-lower chip;

4-a magnet mounting groove;

5-a liquid inlet;

6, a liquid return port;

7-a liquid outlet;

8-a liquid path joint;

9-a first cell sorting tank;

10-liquid inlet flow channel;

11-a return flow path;

12-a second cell sorting tank;

13-a liquid outlet groove;

14-a liquid outlet flow channel;

15-a first auxiliary flow channel;

16-a first branch flow passage;

17-a second auxiliary flow channel;

18-a second branching flow path;

19-a second adapter;

20-a first peristaltic pump;

21-a second peristaltic pump;

22-sample fluid reservoir;

23-a silica gel ring;

24-C-shaped clamp;

25-chip mounting rack; 251-top plate; 252-floor; 253—chip carrier; 254-jacking cylinder;

26-cover.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

As shown in fig. 1-2, a filter-based cell sorter is used for sorting target cells in a blood or urine stock solution.

The cell sorter comprises a plurality of groups of cell sorting components, as shown in fig. 3-6, each group of cell sorting components comprising a filter membrane 1 and a filter membrane chip component. In this example, four sets of cell sorting modules were provided.

The filter membrane chip assembly is used for loading the filter membrane 1. The filter membrane chip assembly comprises an upper chip 2 and a lower chip 3, and the filter membrane 1 is clamped between the upper chip 2 and the lower chip 3.

The filter 1 is a disposable consumable in the shape of a circular sheet. The diameter of the filter membrane 1 is 8 mm, the thickness is 100 microns, tens of thousands of filter holes are uniformly distributed on the filter membrane 1, the aperture of each filter hole is about 8 microns, and the cell retention rate can reach more than 90%.

The outer edge of the filter membrane 1 is fixedly connected with a circle of silica gel ring 23, the silica gel ring 23 plays a sealing role between the filter membrane 1 and the upper chip 2 and the lower chip 3, and can slow down the impact of liquid on the filter membrane 1 so as to prevent the filter membrane 1 from being damaged.

In a preferred embodiment, the upper and lower chips 2 and 3 are provided with magnet mounting grooves 4 for mounting magnets at the four corners thereof, and the upper and lower chips 2 and 3 are attracted to each other by the magnets. This structure makes the loading and the removal operation of the filter membrane 1 convenient.

The upper chip 2 is provided with a liquid inlet 5, a liquid return port 6 and a liquid outlet 7, and the liquid inlet 5, the liquid return port 6 and the liquid outlet 7 are all in the shape of round holes which are vertically communicated. The upper surface of the upper chip 2 is integrally provided with liquid path connectors 8 which are in one-to-one correspondence with the liquid inlet 5, the liquid return port 6 and the liquid outlet 7, and the liquid path connectors 8 are cylindrical.

The lower surface of the upper chip 2 is provided with a first cell sorting groove 9, a liquid inlet channel 10 and a liquid return channel 11. The first cell sorting groove 9 is in a circular sink groove shape, the liquid inlet flow channel 10 is in a strip sink groove shape, and the liquid inlet flow channel 10 is connected with the liquid inlet 5 and the first cell sorting groove 9. The liquid return channel 11 is in a long sinking groove shape, and the liquid return channel 11 is connected with the first cell sorting groove 9 and the liquid return opening 6.

The upper surface of the lower chip 3 is provided with a second cell sorting groove 12, a liquid outlet groove 13 and a liquid outlet flow channel 14. After the upper chip 2 and the lower chip 3 are attracted, the first cell sorting groove 9 and the second cell sorting groove 12 correspond to each other, and the liquid outlet 7 and the liquid outlet groove 13 correspond to each other. The second cell sorting groove 12 is in a circular sink groove shape, the liquid outlet groove 13 is in a circular sink groove shape, the diameter of the liquid outlet groove 13 is smaller than that of the liquid outlet 7, the liquid outlet runner 14 is in a strip sink groove shape, and the liquid outlet runner 14 is connected with the second cell sorting groove 12 and the liquid outlet groove 13.

As shown in fig. 7, the filter membrane 1 and the filter membrane chip assembly are connected with two groups of liquid paths:

the first group of liquid paths are liquid paths for filtering raw liquid, and the raw liquid is urine or blood. The stock solution flows in from the liquid inlet 5 of the upper chip 2 and flows to the first cell sorting groove 9 through the liquid inlet flow channel 10; under the action of gravity, the stock solution in the first cell sorting tank 9 enters the second cell sorting tank 12 through the filter membrane 1, and target cells to be sorted are trapped on the upper surface of the filter membrane 1; the waste liquid entering the second cell sorting tank 12 passes through the liquid outlet channel 14 of the lower chip 3, enters the liquid outlet tank 13, flows out through the liquid outlet 7 of the upper chip 2, and finally is discharged from the cell sorter.

The second group of liquid paths are sample liquid circulating liquid paths, the sample liquid refers to liquid for separating target cells, and the sample liquid is used for subsequent identification and analysis of the target cells. The sample liquid flows in from the liquid inlet 5 of the upper chip 2, flows to the first cell sorting groove 9 through the liquid inlet channel 10, takes away target cells trapped on the upper surface of the filter membrane 1, flows out from the liquid return opening 6 of the upper chip 2 through the liquid return channel 11 of the upper chip 2, flows in from the liquid inlet 5 of the upper chip 2 again, and circulates repeatedly.

The liquid path connector 8 corresponding to the liquid inlet 5 on the upper chip 2 is provided with two adapter connectors 19. The dope filter circuit includes a first peristaltic pump 20. The first peristaltic pump 20 is connected with the first connector of the two adapter connectors 19, and the stock solution is pumped into the liquid inlet 5 through the first peristaltic pump 20. The liquid path joint 8 on the upper chip 2 corresponding to the liquid outlet 7 is connected with the first peristaltic pump 20, and the waste liquid is pumped out of the cell sorter through the first peristaltic pump 20.

The sample fluid circulation fluid path includes a second peristaltic pump 21 and a sample fluid reservoir 22. The second peristaltic pump 21 is connected to the second connector of the two-way connector 19 after being connected to the sample liquid reservoir 22, and the sample liquid is pumped into the liquid inlet 5 through the second peristaltic pump 21. In this embodiment, the sample liquid reservoir 22 is a sampler, and can both add buffer liquid into the sampler and draw sample liquid from the sampler. The liquid path joint 8 on the upper chip 2 corresponding to the liquid return port 6 is connected with the second peristaltic pump 21. The sampler is secured to the cell sorter by a C-clip 24.

It should be noted that, the speed of pumping the stock solution by the first peristaltic pump 20 is relatively slow, and the speed of pumping the sample solution by the second peristaltic pump 21 is relatively fast, because the sample solution in the sample solution reservoir 22 may be mixed with the excessive stock solution when the speed of pumping the stock solution by the first peristaltic pump 20 is relatively fast compared to the speed of pumping the sample solution by the second peristaltic pump 21.

As shown in fig. 2 and 8, four sets of first peristaltic pumps 20 and second peristaltic pumps 21 are disposed within the housing of the cell sorter.

As shown in fig. 3 and 4, in a preferred embodiment, the upper chip 2 is provided with a first auxiliary flow channel 15 on the outer periphery of the first cell sorting groove 9. The first auxiliary flow channel 15 is arc-shaped, a plurality of first branch flow channels 16 which are connected with the first auxiliary flow channel 15 and the first cell sorting groove 9 are arranged between the first auxiliary flow channel 15 and the first cell sorting groove 9, and the plurality of first branch flow channels 16 are arranged in a radial manner. The first auxiliary flow passage 15 and the first branch flow passage 16 have the following functions:

when the raw liquid flows into the first cell sorting groove 9, the raw liquid firstly enters the first auxiliary flow channel 15 and then enters the middle part of the first cell sorting groove 9 through a plurality of first branch flow channels 16, and the flowing mode ensures that the raw liquid is more uniformly distributed on the filter membrane 1, and the effective contact area of the raw liquid and the filter membrane 1 is increased; when the sample liquid flows into the first cell sorting groove 9, the sample liquid firstly enters the first auxiliary flow channel 15, and then enters the middle part of the first cell sorting groove 9 through a plurality of first branch flow channels 16, so that inward impulsive force is generated to strip target cells on the filter membrane 1.

As shown in fig. 4 and 5, in a preferred embodiment, the lower chip 3 is provided with a second auxiliary flow channel 17 on the outer periphery of the second cell sorting groove 12. The second auxiliary flow channel 17 is arc-shaped, a plurality of second branch flow channels 18 which are connected with the second auxiliary flow channel 17 and the second cell sorting groove 12 are arranged between the second auxiliary flow channel 17 and the second cell sorting groove 12, and the plurality of second branch flow channels 18 are arranged in a radial manner. The second auxiliary flow channel 17 is disposed at a side of the second cell sorting groove 12 away from the liquid outlet flow channel 14. The second auxiliary flow passage 17 and the second branch flow passage 18 have the following functions:

when the waste liquid flows out of the second cell sorting tank 12, the waste liquid is guided to the middle part of the second cell sorting tank 12 from the second auxiliary flow channel 17 through a plurality of second branch flow channels 18, and then is intensively guided out of the second cell sorting tank 12 through the liquid outlet flow channel 14, and the flow form avoids the enrichment of the waste liquid in the second cell sorting tank 12, so that the waste liquid can be rapidly discharged along with the diversion.

After the upper chip 2 and the lower chip 3 are correspondingly attracted, the filter membrane 1 is arranged between the first cell sorting groove 9 and the second cell sorting groove 12, and the filter membrane 1 completely covers the first cell sorting groove 9 and the second cell sorting groove 12, the first auxiliary flow channel 15 and the second auxiliary flow channel 17.

As shown in fig. 9, the cell sorter further includes a chip mounting bracket 25, and the sets of cell sorting components are mounted on the chip mounting bracket 25. The chip mounting rack 25 includes a top plate 251, a bottom plate 252, a plurality of chip holders 253, and a plurality of lift cylinders 254. The top plate 251 is fixedly connected with the bottom plate 252, and an opening for the liquid path joint 8 of the upper chip 2 to extend is formed in the top plate 251. The plurality of jacking cylinders 254 are mounted at the bottom of the bottom plate 252, and a piston rod of each jacking cylinder 254 penetrates through the bottom plate 252 and is fixedly connected with a corresponding chip holder 253. The chip holder 253 is provided with a chip placement groove for placing the filter membrane chip assembly, and the front side of the chip placement groove is open, so that the filter membrane chip assembly can be conveniently inserted. After the filter membrane chip assembly is placed on the chip holder 253, the chip holder 253 is lifted upward by the lifting cylinder 254, so that the filter membrane chip assembly is clamped between the top plate 251 and the chip holder 253.

The cell sorter further comprises a cover 26, the cover 26 is rotatably connected to the cell sorter, and the cover 26 is used for covering the filter membrane chip assembly and the liquid path connecting pipeline.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is provided for clarity only, and that the disclosure is not limited to the embodiments described in detail below, and that the embodiments described in the examples may be combined as appropriate to form other embodiments that will be apparent to those skilled in the art.

Claims (8)

1. The utility model provides a cell sorter based on filter membrane, its characterized in that includes stoste filter liquor way, sample liquid circulation liquid way, filter membrane and filter membrane chip subassembly, filter membrane chip subassembly includes chip and lower chip, is equipped with inlet, return liquid mouth, liquid outlet on the last chip, is equipped with first cell sorting groove, inlet channel, return liquid runner on the lower surface of last chip, and the inlet is connected first cell sorting groove, play cistern, liquid runner are equipped with second cell sorting groove on the upper surface of lower chip, first cell sorting groove and second cell sorting groove correspond each other, liquid outlet and liquid groove correspond each other, the filter membrane sets up between first cell sorting groove and second cell sorting groove, the liquid runner is connected the second cell sorting groove with the liquid outlet, the return liquid runner is connected first cell sorting groove with the return liquid mouth, the stoste filter liquor way includes first peristaltic pump, the liquid outlet is connected first peristaltic pump, sample liquid circulation liquid ware and second peristaltic pump are connected the sample liquid ware, the peristaltic pump is connected to the second peristaltic pump.

2. The filter membrane-based cell sorter as in claim 1 wherein a first auxiliary flow channel is provided on the upper chip at the periphery of the first cell sorting channel, the first auxiliary flow channel is in an arc shape, a plurality of first branch flow channels connecting the first auxiliary flow channel and the first cell sorting channel are provided between the first auxiliary flow channel and the first cell sorting channel, and the plurality of first branch flow channels are arranged in a radial shape.

3. The filter membrane-based cell sorter as in claim 1 wherein a second auxiliary flow channel is provided on the periphery of the second cell sorting channel on the lower chip, the second auxiliary flow channel is in an arc shape, a plurality of second branch flow channels connecting the second auxiliary flow channel and the second cell sorting channel are provided between the second auxiliary flow channel and the second cell sorting channel, the plurality of second branch flow channels are arranged in a radial shape, and the second auxiliary flow channel is arranged on one side of the second cell sorting channel far away from the liquid outlet flow channel.

4. The filter-based cell sorter of claim 1 wherein the filter is in the shape of a circular sheet with a diameter of 8 mm and a thickness of 100 microns, and tens of thousands of filter holes are evenly distributed on the filter, each filter hole having a pore size of 8 microns.

5. The filter-based cell sorter of claim 1 wherein a ring of silica gel is fixedly attached to the outer edge of the filter.

6. The filter-based cell sorter of claim 1 wherein magnets are provided at each of four corners of the upper and lower chips, the upper and lower chips being attracted to each other by the magnets.

7. The filter membrane-based cell sorter as in claim 1 wherein the upper surface of the upper chip is integrally provided with liquid path connectors in one-to-one correspondence with the liquid inlet, the liquid return and the liquid outlet.

8. The filter membrane-based cell sorter of claim 1 further comprising a chip mounting rack comprising a top plate, a bottom plate, a plurality of chip holders, a plurality of jacking cylinders, the top plate and the bottom plate being fixedly connected, an opening being provided in the top plate, the plurality of jacking cylinders being mounted at the bottom of the bottom plate, a piston rod of each jacking cylinder passing through the bottom plate and being fixedly connected with a corresponding chip holder, the chip holder being provided with a chip placement groove for placing the filter membrane chip assembly.