CN114832471A - Filter element and filtering device and method thereof - Google Patents

Abstract

A filter element and a filtering device and method thereof, the filter element is provided with micropores for the target substance to be separated in sample liquid to pass through, and the pore diameter of the micropores of the filter element is 10-500 mu m. The filter element can obviously reduce the substance residue with density less than that of the preservation solution in the sample solution, and obtain the high-purity filtered sample solution, thereby obviously reducing the abnormal rate of the sample detection result.

Description

A filter element and its filtering device and method

technical field

The invention relates to the field of sample collection devices and methods, in particular to a filter element and its filtering device and method.

Background technique

In the early screening products for colorectal cancer, the solid-liquid separation of fecal samples is performed in order to absorb the liquid containing relatively few impurities during the process of taking the supernatant, so as to improve the detection accuracy of the product. At present, the main product used for solid-liquid separation of fecal samples is a centrifuge, which is an electrical device.

The existing solid-liquid separation products of stool samples for colorectal cancer detection include:

High-speed centrifuge. The centrifuge was started by placing the sample in the centrifuge rotor and the rotor accelerated to 4000 rpm for 3 minutes. During the high-speed operation of the rotor, the fecal impurities in the colon cancer fecal samples will settle at different rates due to different densities. The overall settling rate increases with the density of the material.

The products used in the existing colorectal cancer stool sample solid-liquid separation technology are mainly sample tubes and centrifuges, such as Xiangyi H2050R high-speed centrifuge.

The specific implementation steps of the existing fecal sample solid-liquid separation method include:

Manually place the mixed sample tube containing the mixture of feces and preservation solution into the centrifuge rotor symmetrically in the center, and close the top cover of the centrifuge.

Start the set 4000 rpm centrifuge program running for 3 minutes.

After the program is over, open the top cover of the centrifuge, and manually take out the centrifuged sample tubes and place them in the sample box.

The existing centrifuge products for colorectal cancer detection fecal sample solid-liquid separation have the following disadvantages:

The solid-liquid separation is not complete. Due to the diversity of human fecal contents, it contains many substances with a density lower than that of the preservation solution, and it is difficult to settle to the bottom of the sample tube no matter how centrifuged (such samples account for about 35% of the total sample), resulting in the next step to take the supernatant. There is a possibility that the operation may fail to take the liquid.

SUMMARY OF THE INVENTION

According to the first aspect, an embodiment provides a filter element, the filter element has micropores through which a target object to be separated in a sample liquid passes, and the micropore diameter of the filter element is 10-500 μm.

According to a second aspect, an embodiment provides a filter device, comprising a filter element and a container for holding a sample liquid, the filter element has micropores for the target to be separated in the sample liquid to pass through, and the filter element is used for It slides along the inner wall of the container to filter the sample liquid.

According to a third aspect, an embodiment provides a filtering method, comprising: placing the filter element in the first aspect into a container containing a sample liquid, and pressing the filter element down, wherein the container is located in the container The sample liquid under the filter element enters the filter element from the lower surface of the filter element, flows through the micropores of the filter element, and then reaches the top of the filter element, and the liquid above the filter element is the filtered sample liquid.

According to a filter element and its filtering device and method according to the above-mentioned embodiment, the filter element of the present invention can significantly reduce the residual substances in the sample liquid whose density is lower than that of the preservation liquid, and obtain a high-purity filtered sample liquid, thereby significantly reducing the abnormal rate of sample detection results.

Description of drawings

1 is a schematic diagram of the filter element structure of an embodiment;

2 is a front view of a filter element of an embodiment;

3 is a top view of a filter element according to an embodiment;

FIG. 4 is a schematic structural diagram of a sampling tube according to an embodiment.

Numeral description: 1, filter element; 11, cylinder part; 12, lower surface; 13, upper surface; 2, pipe body; 21, nozzle; 22, pipe cover.

Detailed ways

The present invention will be further described in detail below through specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments have used associated similar element numbers. In the following embodiments, many details are described so that the present application can be better understood. However, those skilled in the art will readily recognize that some of the features may be omitted under different circumstances, or may be replaced by other elements, materials, and methods. In some cases, some operations related to the present application are not shown or described in the specification, in order to avoid the core part of the present application from being overwhelmed by excessive description, and for those skilled in the art, these are described in detail. The relevant operations are not necessary, and they can fully understand the relevant operations according to the descriptions in the specification and general technical knowledge in the field.

Additionally, the features, acts, or characteristics described in the specification may be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can also be exchanged or adjusted in order in a manner obvious to those skilled in the art. Therefore, the various sequences in the specification and drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a necessary order unless otherwise stated, a certain order must be followed.

The serial numbers themselves, such as "first", "second", etc., for the components herein are only used to distinguish the described objects, and do not have any order or technical meaning.

As used herein, a "sampling tube" is a tubular tool used to contain and/or transport a biological sample, typically placed on a centrifuge device for centrifugation. Herein, "sampling tube" and "sample tube" are used interchangeably.

According to the first aspect, in an embodiment, a filter element is provided, the filter element has micropores for the target to be separated in the sample liquid to pass through, and the micropore diameter of the filter element is 10-500 μm. The filter element can be sold as a separate product. The micropore diameter of the filter element is preferably 100 to 500 μm, more preferably 300 to 500 μm, more preferably 350 to 400 μm, and more preferably 375 μm. The pore size of the filter element includes but is not limited to 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 125 μm, 150 μm, 175 μm, 200 μm, 225 μm, 250 μm, 275 μm, 300 μm, 325 μm, 350 μm, 375 μm , 450μm, 475μm, 500μm.

In one embodiment, the material of the filter element includes, but is not limited to, polyurethane, polypropylene or polyethylene, preferably polyurethane.

In one embodiment, the density of the filter element is ≥20kg/m ³ , preferably 25-35kg/m ³ , more preferably 30kg/m ³ . The density of the filter element includes but is not limited to 20kg/m ³ , 21kg/m ³ , 22kg/m ³ , 23kg/m ³ , 24kg/m ³ , 25kg/m ³ , 26kg/m ³ , 27kg/m ³ , 28kg/m ³ , 29kg/m ³ , 30kg/m ³ , 31kg/m ³ , 32kg/m ³ , 33kg/m ³ , 34kg/m ³ , 35kg/m ³ .

If the density of the filter element is too small, it may cause the filter element to float and be difficult to handle; if the density is too large, the radial elasticity of the filter element will be reduced, which may make it difficult for the filter element to be pushed into the bottom of the sampling tube by the suction head.

In one embodiment, the target includes, but is not limited to, cells.

In one embodiment, the cells include, but are not limited to, tumor cells.

In one embodiment, tumor cells include, but are not limited to, colorectal cancerous tumor cells.

In one embodiment, the sample fluid includes, but is not limited to, fecal sample fluid.

In one embodiment, the maximum diameter of the filter element is less than or equal to the inner diameter of the container for holding the sample liquid, or slightly larger than the inner diameter of the container.

In one embodiment, the filter element is cylindrical.

In one embodiment, the height of the filter element is ≥5 mm, preferably 5-20 mm, more preferably 5-10 mm.

In one embodiment, the diameter of the filter element is ≥5 mm, preferably 5-30 mm, more preferably 10-20 mm.

According to a second aspect, in one embodiment, a filter device includes the filter element according to any one of the first aspects and a container for holding a sample liquid, the filter element has micropores for the target to be separated in the sample liquid to pass through. , the filter element is used to slide along the inner wall of the container to filter the sample liquid.

In one embodiment, the filter element is used to filter impurities in the sample liquid. The particle size of the substances other than the target (mainly impurities) is larger than the micropore diameter of the filter element and cannot pass through the micropore, while the target material can enter the other side of the filter element from the micropores on one side of the filter element, so as to realize the separation of the target material , and the sample liquid on the other side contains almost no impurities.

In one embodiment, at least a part of the outer wall of the filter element can be in close contact with the inner wall of the container containing the sample liquid and can slide along the inner wall.

In one embodiment, the micropore diameter of the filter element is 10-500 μm, preferably 100-500 μm, and more preferably 300-500 μm. The pore size of the filter element includes, but is not limited to, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 450 μm, 500 μm.

If the pore size of the pores is too small, the target cells or nucleic acids will be difficult to pass through the filter element, resulting in a decrease in the detection sensitivity of the experimental results; if the pore size is too large, large particles of impurities will pass through the filter element, causing the suction head to be blocked in the sampling process, resulting in sampling failure.

In one embodiment, the material of the filter element includes, but is not limited to, polyurethane, polypropylene, polyethylene, stainless steel or ceramics.

In one embodiment, the density of the filter element is ≥20kg/m ³ , preferably 25-35kg/m ³ , more preferably 30kg/m ³ . The density of the filter element includes but is not limited to 25kg/m ³ , 26kg/m ³ , 27kg/m ³ , 28kg/m ³ , 29kg/m ³ , 30kg/m ³ , 31kg/m ³ , 32kg/m ³ , 33kg/m ³ , 34kg/m ³ , 25kg/m ³ .

If the density of the filter element is too small, it may cause the filter element to float up and be difficult to handle; if the density is too large, the radial elasticity of the filter element will decrease, which may make it difficult for the filter element to be pushed into the bottom of the sampling tube by the suction head.

In one embodiment, the filter element has a cylindrical portion. The shape of the filter element is not limited, and can be various shapes such as a cylinder, a cone, etc., which can make the filter element slide down against the inner wall of the container, and various shapes for filtering the sample liquid are suitable for the present invention. The inner cavity of the container for holding the sample liquid is usually cylindrical. Therefore, the filter element is preferably a cylinder or a cylinder with an inverted conical bottom, which can effectively prevent the filter element from drifting in the sample liquid, resulting in incomplete filtration.

In one embodiment, the target includes, but is not limited to, cells.

In one embodiment, the cells include, but are not limited to, tumor cells.

In one embodiment, tumor cells include, but are not limited to, colorectal cancerous tumor cells.

In one embodiment, the sample fluid includes, but is not limited to, fecal sample fluid.

In one embodiment, the maximum diameter of the filter element is less than or equal to the inner diameter of the container for holding the sample liquid, or slightly larger than the inner diameter of the container. The filter element usually has a certain deformation, so that the outer wall of the filter element is close to the inner wall of the container, so as to prevent the sample liquid from flowing into the top of the filter element from the gap between the filter element and the inner wall of the container without being filtered by the filter element.

In one embodiment, the container used to hold the sample liquid can be any existing container, specifically a sampling tube. The shape, specification, model, and manufacturer of the sampling tube are not limited, and any sampling tube is suitable for this invention.

According to a third aspect, in one embodiment, a filtering method is provided, comprising: placing the filter element according to any one of the first aspects into a container containing the sample liquid, pressing the filter element down, and a filter element located below the filter element in the container is The sample liquid enters the filter element from the lower surface of the filter element, flows through the micropores of the filter element, and then reaches the top of the filter element. The liquid above the filter element is the filtered sample liquid.

In one embodiment, it also includes drawing the required sample liquid from the liquid above the filter element.

In one embodiment, the sampler is controlled by the control system to draw the required sample liquid from the liquid above the filter element.

In one embodiment, the filter element is controlled by the control system to enter the container containing the sample liquid, the filter element is pressed down, and the sample liquid located under the filter element in the container infiltrates from the lower surface of the filter element and flows through the micropores of the filter element. , and then reach the top of the filter element, the liquid above the filter element is the filtered sample liquid.

In one embodiment, the control system includes, but is not limited to, an embedded system, a programmable logic controller (PLC), and the like.

In one embodiment, the present invention provides a filter element for realizing solid-liquid separation of stool samples for colorectal cancer detection. Compared with the solid-liquid separation method adopted by existing centrifuge products, the filter element can greatly improve the solid-liquid separation efficiency. Substances with a density lower than that of the preservation solution in the sample solution were significantly reduced.

In one embodiment, the filter element structure of the present invention is mainly developed for automated application scenarios, and the filter element can be automatically grabbed and put into the sampling tube to realize the filtration of large-particle impurities.

In the prior art, some filter elements are provided with pores for the purpose of fully mixing the sample and the preservation liquid, while the filter element of the present invention has a porous structure, which can filter large particles of impurities and is suitable for automated sampling scenarios.

Example 1

FIG. 1 is a schematic diagram of the three-dimensional structure of the filter element. The filter element 1 is in the form of a cylinder and has a cylinder portion 11 , a lower surface 12 and an upper surface 13 .

FIG. 2 is a front view of the filter element. The height h of the filter element 1 can be 6-10 mm, which is only an example here, and other heights are also possible.

FIG. 3 is a top view of the filter element, and the diameter d of the filter element 1 may be 10-15 mm.

Figure 4 shows a schematic diagram of the structure of the sampling tube. The tube body 2 has a cylindrical inner cavity, and the inner cavity is filled with the sample liquid. The top of the tube body 2 is provided with a nozzle 21 and a tube cover 22 for tightly covering the nozzle 21. After taking out the tube cover 22, put the filter element 1 into the inner cavity of the tube body 2 from the nozzle 21, and the outer wall of the column body 11 is closely attached to the inner wall of the sampling tube 1. The filter element is inserted into the bottom of the sampling tube. The sample liquid enters the filter element from the lower surface 12 of the filter element 1, and then flows out from the upper surface 13. The liquid above the filter element 1 is the filtered sample liquid. This structure and the corresponding filtration method significantly reduce the residue of substances whose density is lower than that of the preservation liquid. Significantly improves separation.

In this example, a 10 mL sampling tube (93 types) produced by Shenzhen Medico Biomedical Technology Co., Ltd. was used for the subsequent filter element test experiment. But not limited to this, the filter element of the present invention is applicable to any sampling tube.

Based on the size drawing of the colorectal cancer sampling tube, the diameter of the single cell and tissue cells of the colorectal cancer tumor, a filter structure is designed, which has the following characteristics:

1. Tumor cells and normal cells in feces are easy to permeate, and fecal impurities (mainly food residues) larger than or equal to the diameter of the suction tip are not easily permeable; the diameter of a single colorectal cancerous tumor cell is about 10 μm, and the number of exfoliated cells in the human intestinal tract is generally more For tissue composed of cells, the filter element designed in this embodiment has a pore size larger than 10 μm, which can allow tumor cells and normal cells in feces to pass through smoothly.

2. The structure is easy to put into the sampling tube manually or automatically, and it is easy to realize the vertical movement from the nozzle to the bottom of the tube to complete the filtering action.

3. The structure is simple and easy to produce, and the cost is low.

4. The diameter of the conventional 1000μL manual pipette tip is 500μm, and the diameter of the automatic 1000μL pipette tip is 1000μm; Sampling in liquid.

5. The filter element of this embodiment can withstand a certain degree of deformation, and is suitable for the sampling tube cavity structure of the inverted boss with a large diameter and a gradually narrowed bottom.

6. The material production process of the filter element can be selected from foaming, weaving, stamping and injection molding. The manufacturing cost is foaming, stamping, weaving and injection molding in order from low to high. In this embodiment, the lowest cost foam material is selected.

The filter element structure designed in the present embodiment is a cylinder, and different sizes are designed to test whether it meets the requirements. The test samples are as follows:

Table 1 Filter Specifications

The density of the third and fourth batches of polyurethane was 20kg/m ³ , and the density of the fifth and sixth batches of high-density polyurethane was 30kg/m ³ .

The specific steps of the test experiment are as follows (the next test will only be performed if the previous test is passed):

The first test experiment is to test the passability of the filter element in the sampling tube.

Test method: Place the filter element horizontally at the mouth of the sampling tube containing the liquid sample. If the pipette with the tip tied can easily push the filter element into the bottom of the sampling tube, it will be judged as qualified; otherwise, it will be judged as unqualified. This step is the compatibility test of the filter element and the sampling tube.

The second step of the test experiment is to test the passability of the filter element to the supernatant in the fecal sample.

Test method: Put the filter element into the liquid sample of the sampling tube, and observe the passage of the liquid in the filter element. If the clear liquid can completely pass through within 1s, it is qualified. Otherwise, if it is difficult for the clear liquid to pass through the filter element completely due to the floating of the filter element, it will be judged as unqualified.

The third step of the test experiment is to test the influence of the filter element on the final result of colon cancer detection.

Test method: 540 samples were divided into three groups, namely control group, experimental group 1 and experimental group 2, with 180 samples in each group. The samples were divided into sampling tubes, the total volume of each sample was 5 mL, and the volume of the solid content of the sample was 1.5 mL. The specifications and parameters of the centrifuge are set as follows: Xiangyi H2050R, 4000 rpm, 3 min. Pipette: Eppendorf 1000 μL manual pipette. Automatic sampling instrument: MGISTP-7000 automatic cup dispensing system made by MGI.

The descriptions of each group are as follows:

Control group: no filter element was added, centrifuged, and the filtered supernatant was collected by a manual pipette.

Experimental group 1: add filter element, centrifuge, and take the supernatant automatically.

Experimental group 2: add filter element, do not centrifuge, and take the supernatant automatically.

According to the above rules, a control group, an experimental group 1 and an experimental group 2 were set up for control experiments. The eligibility criteria are as follows: in the data comparative analysis results of experimental group 1 or experimental group 2 and the control group, the agreement rate of strong positive ≥ 90%, the agreement rate of weak positive ≥ 75%, and the agreement rate of negative ≥ 90%.

Table 2 Filter test results

The first test results:

The filter element is made of stainless steel, ceramic, and polyethylene. The first step is unqualified. The test results of polypropylene, polyurethane and high-density polyurethane are qualified.

The second step test results:

The filter element is made of polypropylene, polyurethane and high-density polyurethane. The test results are qualified.

The third step test results:

According to the test results, it is confirmed that the qualified filter element is a high-density polyurethane filter element with a cylindrical shape, a diameter of 14.2 mm, a height of 10 mm, and a pore size of 375 μm.

Repeat the test experiment as follows:

Samples were subjected to two replicate experiments. The first experiment of the sample: the original group was no filter element, centrifugation, and manual sampling. The samples were divided into three groups in the second experiment, and the treatment methods of each group were as follows:

1) The first group is to filter with filter element, and then use MGISTP-7000 to automatically take the supernatant.

2) The second group is to filter with a filter element first, then centrifuge with a centrifuge, and then use MGISTP-7000 to automatically take the supernatant.

3) The third group is no filter element, centrifuge centrifuge, and then manually take the supernatant.

The specific steps for filtration with filter elements and subsequent automated sampling are as follows:

(1) Take the sampling tube out of the sample box and open the tube cover.

(2) Use tweezers to horizontally hold the cylinder at 0-6mm on the upper end of the filter element, put the filter element into the nozzle horizontally, and sink to a depth of about 2-3mm. The tweezers do not contact the nozzle during operation.

(3) Cover the sampling tube cap, screw it tightly, and completely push the filter element into the sampling tube.

(4) Place the sampling tube after adding the filter element on the carrier of MGISTP-7000, and select the corresponding parameters to start the device.

(5) After the operation of the equipment is completed, a sample with solid-liquid separation and 1 mL of the supernatant in the deep-well plate is obtained.

The complete colorectal cancer detection experiment of this filter element has been repeated with 800 samples, and the results are as follows:

Table 3 Filter test results

It can be seen from Table 3 that, taking the second group as a reference, the strong positive, weak positive, and positive consistency rates of the first group are higher than those of the third group, indicating that the automatic sampling after adding the filter element improves the detection accuracy.

This embodiment provides a filter element for solid-liquid separation of stool samples for colorectal cancer detection. The specific information of the filter is as follows:

Main material: polyurethane (polymers containing -NHCO- groups on the main chain are collectively referred to as polyurethane formate for short polyurethane). Specifically, polyester polyols (about 40% by mass in the total raw materials) and toluene diisocyanate (about 35% by mass in the total raw materials) are used as the main raw materials for polyurethanes, and the remaining 25 % is all kinds of auxiliary materials, including tertiary ammonium compounds, foam stabilizers, water, colorants and tin catalysts. The polyurethane used for preparing the filter element in this example was purchased from Dongguan Shengyi Environmental Protection Material Co., Ltd.

Manufacturing process: one-step foaming method, die-cutting.

Material density: 30kg/m ³ (ie high density polyurethane).

Micropore diameter: 375 μm.

The applicable scene of this example is the detection of intestinal cancer. The fecal samples containing the preservation solution are subjected to solid-liquid separation before the cup is divided. The sample tube suitable for the filter element of this example is Shenzhen Medico 10mL sampling tube-93. For sample tubes produced by other manufacturers, the shape and size of the filter element can be adjusted to fit. It can slide down the inner wall of the sample tube under the slight deformation to realize the filtration of the sample liquid.

The steps for realizing solid-liquid separation of the filter element are as follows:

1. In the biological safety cabinet, the experimenter takes a 10mL sampling tube containing the mixed fecal sample from the sample box and places it vertically on the biological safety cabinet operating table.

2. The experimenter holds the transparent bottle body of the 10mL sampling tube tightly with one hand and keeps the bottom of the sampling tube horizontal, and the other hand holds the bottle cap of the 10mL sampling tube tightly, and the hand holding the bottle cap rotates counterclockwise several times until the bottle cap is unscrewed. , invert the unscrewed cap of the sampling tube horizontally on the operating table of the biological safety cabinet.

3. Keep the hand holding the bottle body still, pick up the tweezers with the other hand to pick up the cylindrical surface of the filter element (cylinder, outer diameter 14.2mm, height 10mm, material of high-density polyurethane, foaming process), and it is opposite to the upper end surface of the filter element The height of the filter element should not exceed 5mm, and the filter element should be placed horizontally into the nozzle of the sampling pipe.

4. After placing the tweezers in the corresponding position, pick up the cover upside down on the operating surface of the biological safety cabinet, rotate the wrist to put it straight, cover the tube cover and push the filter element protruding from the mouth of the sampling tube into the sampling tube. Turn the cap clockwise until it is tight.

5. Take out all the sampling tubes and put them on the carrier of the MGISTP-7000 automatic cupping equipment made by MGI.

6. On the interface of the host computer, select the type of sampling tube, the position of sampling tube, the type of suction head, the position of suction head, the type of deep-well plate and the position of deep-well plate, close the window, and start the cup dispensing program.

7. After the equipment is finished running, open the equipment window and take out the deep well plate.

So far, the solid-liquid separation of stool samples for colorectal cancer detection has been completely completed, and the operation of taking the supernatant has been completed.

In one embodiment, the present invention solves the problem of incomplete solid-liquid separation in the current centrifugal method by pre-filtering the sampling tube, and realizes that the abnormal rate of one-time sampling of stool samples for colorectal cancer detection is from more than 35% to less than 1%. change.

In one embodiment, the present invention eliminates the problem that the existing automatic cup-dispensing system MGISTP-7000 cannot avoid the problem that the suspension of the liquid surface of the fecal sample blocks the suction head, successfully realizes the automation of the process of taking the supernatant, and improves the efficiency of taking the supernatant by 100%. %.

In one embodiment, the present invention is simple to operate, omits the currently used centrifugation link, reduces the need for frequent manual picking and placement of sampling tubes in the centrifugation method, and greatly reduces the labor intensity of personnel.

In one embodiment, the filter element product used in the present invention has low cost and is easy to obtain, and can be exchanged for low-cost materials to greatly improve the quality and efficiency, which is beneficial to reduce the cost of sample liquid processing.

The following table shows the unloading results of the samples obtained by manually taking the supernatant after centrifugation and by adding a filter element to automatically take the supernatant in this example.

Table 4 results of disembarkation data obtained by manually taking supernatant after centrifugation

sample number Number of samples Positive initial test Positive rate number of failed samples failure rate WH2201230001 90 18 20.0% 1 1.1% WH2201230002 90 twenty two 24.4% 1 1.1% WH2201230003 90 twenty two 24.4% 0 0.0% WH2201230005 90 twenty two 24.4% 1 1.1% WH2201230006 90 25 27.8% 0 0.0% WH2201260004 90 twenty four 26.7% 0 0.0% Total 540 133 24.6% 3 0.6%

Table 5 adds filter element automation and gets off the machine data result that supernatant obtains

sample number Number of samples Positive initial test Positive rate number of failed samples failure rate WH2201230001 90 30 33.3% 0 0.0% WH2201230002 90 30 33.3% 0 0.0% WH2201230003 90 30 33.3% 0 0.0% WH2201230005 90 30 33.3% 0 0.0% WH2201230006 90 30 33.3% 0 0.0% WH2201260004 90 30 33.3% 0 0.0% Total 540 180 33.3% 0 0.0%

In Table 4 and Table 5, the number of failed samples refers to the number of samples that failed to be sampled due to clogging of the tip.

As can be seen from the results in Table 4 and Table 5, in terms of failure rate, the supernatant obtained after centrifugation without the use of a filter element, the failure rate of subsequent sequencing is significantly higher than that of adding a filter element to automatically take the supernatant.

In terms of positive rate, the supernatant was manually collected after centrifugation, and the positive rate of subsequent detection results fluctuated greatly and the consistency was poor. The positive rate of the supernatant taken automatically by adding filter element has almost no fluctuation, and the consistency rate is high.

The above specific examples are used to illustrate the present invention, which are only used to help understand the present invention, and are not intended to limit the present invention. For those skilled in the art to which the present invention pertains, according to the idea of the present invention, several simple deductions, modifications or substitutions can also be made.

Claims (10)

1. A filter element, characterized in that, the filter element has micropores through which a target object to be separated in a sample liquid passes, and the micropore diameter of the filter element is 10-500 μm. 2 . The filter element according to claim 1 , wherein the micropore diameter of the filter element is 100-500 μm, preferably 300-500 μm, more preferably 350-400 μm, and more preferably 375 μm. 3 . 3. The filter element according to claim 1, wherein the material of the filter element comprises polyurethane, polypropylene or polyethylene. 4 . The filter element according to claim 1 , wherein the filter element has a density of ≥20 kg/m ³ , preferably 25-35 kg/m ³ , and more preferably 30 kg/m ³ . 5. The filter element according to claim 1, wherein the filter element is in the form of a cylinder; Preferably, the height of the filter element is ≥5mm, preferably 5-20mm, more preferably 5-10mm; Preferably, the diameter of the filter element is ≥5 mm, preferably 5-30 mm, more preferably 10-20 mm. 6 . A filter device, characterized in that it comprises the filter element according to any one of claims 1 to 5 and a container for holding a sample liquid, wherein the filter element has a micro-filter for the target object to be separated in the sample liquid to pass through. The filter element is used for sliding along the inner wall of the container to filter the sample liquid. 7 . The filter device according to claim 6 , wherein at least part of the outer wall of the filter element can be closely attached to the inner wall of the container containing the sample liquid and can slide along the inner wall. 8 . 8. The filter device according to claim 6, wherein the density of the filter element is ≥20kg/m ³ , preferably 25-35kg/m ³ , preferably 30kg/m ³ ; Preferably, the target comprises cells; Preferably, the cells comprise tumor cells; Preferably, the tumor cells include colorectal cancerous tumor cells; Preferably, the sample liquid includes stool sample liquid; Preferably, the maximum diameter of the filter element is less than or equal to the inner diameter of the container for holding the sample liquid, or slightly larger than the inner diameter of the container. 9 . A filtration method, characterized in that , comprising: placing the filter element according to any one of claims 1 to 5 into a container containing a sample liquid, and pressing the filter element down, wherein the container is located in the container The sample liquid under the filter element enters the filter element from the lower surface of the filter element, flows through the micropores of the filter element, and then reaches the top of the filter element, and the liquid above the filter element is the filtered sample liquid. 10. The filtering method according to claim 9, further comprising drawing the required sample liquid from the liquid above the filter element; Preferably, the sampler is controlled by the control system to draw the required sample liquid from the liquid above the filter element; Preferably, the target comprises cells; Preferably, the cells comprise tumor cells; Preferably, the tumor cells include colorectal cancerous tumor cells; Preferably, the sample liquid includes stool sample liquid; Preferably, the maximum diameter of the filter element is less than or equal to the inner diameter of the container for holding the sample liquid, or slightly larger than the inner diameter of the container.

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