Bacterial isolation chip and isolation method

Abstract

The application relates to a bacterial separation chip and a separation method. The bacterial separation chip comprises a chip body and a magnetic component. The chip body is formed with a separation flow channel for accommodating a sample. The magnetic component is connected to the chip body. At least part of the magnetic component is located in the separation flow channel and at an inner wall surface of the separation flow channel. The magnetic component is used for capturing bacteria in the sample. A shearing fluid is arranged in the separation flow channel. The sample has separation particles. The bacteria in the sample move to the inner wall surface of the separation flow channel under the action of the shearing fluid and the separation particles. The bacterial separation chip of the application realizes directional movement of bacteria and rapid capture and separation of the bacteria.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bacterial separation, and in particular to a bacterial separation chip and a separation method. BACKGROUND

[0002] The premise of preventing and controlling pathogenic bacteria pollution of animal-derived food is to realize rapid, sensitive and accurate detection of pathogenic bacteria. The detection process of pathogenic bacteria generally includes sample collection, pathogen separation and pathogen detection. Among them, pathogen separation is to separate high-purity and high-concentration target bacteria to be detected from complex samples, which seriously affects the subsequent detection.

[0003] The concentration of the bacteria to be detected in biological and food samples is very low, so the conventional method generally uses culture method for 8 to 18 hours of pre-enrichment, which greatly increases the overall detection time. In order to reduce the time of pathogen separation, the rapid separation method in the related art mainly includes magnetic separation method, which captures target bacteria by constructing immune magnetic beads specific selection, and further applies a magnetic field to enrich magnetic bacteria, so as to realize high-purity enrichment of pathogenic bacteria. However, the magnetic separation method in the related art needs repeated magnetic separation steps, and the magnetic separation device is often small, and the magnetic field acting space is limited, so that the sample volume is generally small. When the sample amount is large, the effective separation of the target object can only be realized by multiple separation, it is difficult to realize rapid separation of bacteria, and the speed of bacterial separation needs to be improved. SUMMARY

[0004] The bacterial separation chip provided by the embodiments of the present application at least partially solves the above technical problems.

[0005] In order to achieve the above purpose, according to the first aspect of the present application, a bacterial separation chip is provided, comprising:

[0006] A chip body is formed with a separation flow channel, and the separation flow channel is used to accommodate a sample.

[0007] A magnetic component is connected to the chip body, at least part of the magnetic component is located in the separation flow channel and at the inner wall surface of the separation flow channel, and the magnetic component is used to capture bacteria in the sample.

[0008] Wherein, the separation flow channel is provided with a shear fluid, and the sample has separation particles, so that the bacteria in the sample move to the inner wall surface of the separation flow channel under the action of the shear fluid and the separation particles.

[0009] Optionally, the shear fluid is a biocompatible liquid.

[0010] Optionally, the separation particles are polystyrene microspheres.

[0011] Optionally, the density of the separation particles is between 1.05 g / cm 3 and 1.09 g / cm 3 ; and / or,

[0012] The concentration of the separation particles is between 3.5 x 10 12 and 5.5 x 10 12 ; and / or,

[0013] The size of the separation particles is between 6 μm and 8 μm.

[0014] Optionally, the magnetic component comprises an immunomagnetic bead chain, one end of the immunomagnetic bead chain is connected to the inner side wall of the separation flow channel, and the other end of the immunomagnetic bead chain extends to the center of the separation flow channel.

[0015] Optionally, the magnetic component comprises at least two immunomagnetic bead chains, the at least two immunomagnetic bead chains comprise a first immunomagnetic bead chain and a second immunomagnetic bead chain, and the first immunomagnetic bead chain and the second immunomagnetic bead chain are oppositely arranged.

[0016] Optionally, the number of the first immunomagnetic bead chains is a plurality, the number of the second immunomagnetic bead chains is a plurality, the plurality of the first immunomagnetic bead chains are arranged side by side, and the plurality of the second immunomagnetic bead chains are arranged side by side.

[0017] Optionally, the magnetic component further comprises a ferromagnetic substance and a magnet, the ferromagnetic substance is arranged on the outer side wall of the chip body, the magnet is connected to the side of the ferromagnetic substance away from the chip body, the ferromagnetic substance and the magnet are used to construct a high gradient magnetic field, and the immunomagnetic bead chain is located in the high gradient magnetic field.

[0018] Optionally, a first end of the chip body is formed with an inlet in communication with the separation flow channel, and a second end of the chip body is formed with an outlet in communication with the separation flow channel.

[0019] According to a second aspect of the present application, a bacterial separation method is also provided, comprising:

[0020] injecting a shearing fluid into the separation flow channel of the chip body to form a shearing flow field in the separation flow channel;

[0021] arranging an immunomagnetic bead chain on the inner side wall of the separation flow channel and constructing a high gradient magnetic field at the chip body so that the immunomagnetic bead chain is located in the high gradient magnetic field;

[0022] mixing a sample to be separated with separation particles to obtain a mixed sample;

[0023] Injecting the mixed sample into the separation flow channel, so that the bacteria in the mixed sample flow to the edge of the separation flow channel under the action of the shearing fluid and the separation particles.

[0024] In the bacterial separation chip of the embodiments of the present application, the sample and the separation particles are mixed and then injected into the separation flow channel, so that the mixture of the sample and the separation particles flows along the separation flow channel, and the shearing fluid is arranged in the separation flow channel. Under the action of the shearing fluid, the bacteria in the sample collide with the separation particles, so that the bacteria move to the edge of the separation flow channel, i.e. the inner wall surface of the separation flow channel, under the action of the fluid shearing force and the collision force of the separation particles, realizing directional movement of the bacteria. At the same time, the inner wall surface of the separation flow channel is provided with a magnetic component, which can capture the bacteria in the sample when the bacteria move to the inner wall surface of the separation flow channel. That is, the bacteria in the sample can be moved to the inner wall surface of the separation flow channel by cooperation of the shearing fluid and the separation particles, so that the bacteria in the sample are concentrated at the inner wall surface of the separation flow channel, and the magnetic component for capturing the bacteria is arranged at the inner wall surface of the separation flow channel. The magnetic component can effectively capture the bacteria in the sample, realizing rapid capture and separation of the bacteria, without repeated magnetic separation and capture of the bacteria in the sample. When capturing the bacteria, the sample flows along the separation flow channel, so that when the sample amount is large, the sample does not need to be separated for multiple times, improving the bacterial separation speed and reducing the detection cost.

[0025] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creating any creative labor.

[0027] In order to more completely understand the present application and its beneficial effects, the following will be described in conjunction with the drawings, wherein the same reference numerals in the following description represent the same parts.

[0028] Figure 1 is a structural schematic diagram of a bacterial separation chip provided in an exemplary embodiment of the present disclosure;

[0029] Figure 2 is a flowchart of a bacterial separation method provided in an exemplary embodiment of the present disclosure.

[0030] Explanation of reference numerals:

[0031] 1, chip body; 2, magnetic component; 3, separation particle; 4, bacteria; 11, separation flow channel; 12, inlet; 13, outlet; 21, immunomagnetic bead chain; 22, ferromagnetic substance; 23, magnet. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0033] According to the first aspect of the present application, referring to Figure 1 The present application provides a bacteria separation chip. The bacteria separation chip comprises a chip body 1 and a magnetic component 2, the chip body 1 is formed with a separation flow channel 11 for accommodating a sample, and the magnetic component 2 is connected to the chip body 1, at least part of the magnetic component 2 is located in the separation flow channel 11 and at the inner wall surface of the separation flow channel 11, and the magnetic component 2 is used for capturing bacteria 4 in the sample.

[0034] Wherein, a shearing fluid is arranged in the separation flow channel 11, and the sample has a separation particle 3, so that the bacteria in the sample move to the inner wall surface of the separation flow channel 11 under the action of the shearing fluid and the separation particle 3.

[0035] It can be understood that after the sample and the separation particle 3 are mixed and injected into the separation flow channel 11, the mixture of the sample and the separation particle 3 flows along the separation flow channel 11, and the shearing fluid is arranged in the separation flow channel 11, under the action of the shearing fluid, the bacteria 4 in the sample will collide with the separation particle 3, so that the bacteria 4 move to the edge of the separation flow channel 11, i.e. the inner wall surface of the separation flow channel 11, under the action of the fluid shearing force and the collision force of the separation particle 3, realizing the directional movement of the bacteria 4. At the same time, the inner wall surface of the separation flow channel 11 is provided with the magnetic component 2, when the bacteria 4 move to the inner wall surface of the separation flow channel 11, the magnetic component 2 can capture the bacteria 4 in the sample. That is to say, through the cooperation of the shearing fluid and the separation particle 3, the bacteria 4 in the sample can be moved to the inner wall surface of the separation flow channel 11, so that the bacteria 4 in the sample are concentrated at the inner wall surface of the separation flow channel 11, and the inner wall surface of the separation flow channel 11 is provided with the magnetic component 2 for capturing the bacteria 4, the magnetic component 2 can effectively capture the bacteria 4 in the sample, realizing the rapid capture and separation of the bacteria 4, without repeatedly capturing the bacteria 4 in the sample by magnetic separation, and when capturing the bacteria 4, the sample flows along the separation flow channel 11, so that when the sample amount is large, it is also unnecessary to separate for multiple times, improving the separation speed of the bacteria 4 and reducing the detection cost.

[0036] It can be understood that in the related art, when the volume of the sample is large, the bacterial separation effect needs to be ensured by increasing the magnetic field strength, increasing the number of immunomagnetic beads, etc., resulting in high cost. However, in the present application, the bacteria in the sample can be made to move directionally to the inner wall surface of the separation flow channel 11 in the process of moving along the separation flow channel 11 by the cooperation of the shearing fluid and the separation particles 3, and then the bacteria in the sample can be effectively captured by arranging the magnetic component 2 at the inner wall surface of the separation flow channel 11, so that the rapid continuous flow separation of the bacteria in the large-volume sample is realized.

[0037] It can be understood that the rapid flow of fluid in the living body can provide a reference for separating bacteria in a large-volume sample. Blood and blood vessels form a complex and well-functioning fluid pathway, and the flow rate in the arterial blood vessels can reach 180-220 mm / s (about 300 mL / min). In addition, blood is a viscous suspension composed of red blood cells, white blood cells and platelets, among which the platelets of about 2 μm can adhere to the damaged site of the blood vessel through the edge effect, so as to realize the healing of the blood vessel. When the blood vessel is damaged, in order to adhere to the damaged surface, the platelets must be close enough to the wound, i.e. the platelet margination. The platelet margination is caused by the interaction between the platelets and the red blood cells in the flowing blood, and the collision between the red blood cells and the platelets caused by the shear leads to the deflection of the circulating platelets to the blood vessel wall, and the platelets moving along the blood vessel wall are combined through the adhesion proteins on the surface of the blood vessel wall, so that the platelets can realize the rapid movement towards the blood vessel wall surface at high shear speed and adhere to the surface.

[0038] The separation particles 3 in the present application can be compared to red blood cells, the bacteria in the sample can be compared to platelets, and the magnetic component 2 can be compared to the proteins on the surface of the blood vessel wall that can specifically adhere to the platelets. In addition, the sub-micron particles do not have the edge effect in the red blood cell suspension, while the platelets are a kind of oblate spheroids with a length-diameter ratio of 1:2, which is close to the size and shape of common bacteria (such as Escherichia coli and Salmonella bacteria), and can produce significant edge effect. Therefore, by the cooperation of the shearing fluid and the separation particles 3, the bacteria can be separated in the process of rapid flow of the sample, which is beneficial to solve the bottleneck problem of slow sample flow in the related art.

[0039] In some embodiments, the shearing fluid is a biocompatible liquid, such as a phosphate buffer solution, etc.

[0040] In some embodiments, the separation particles 3 are, for example, polystyrene microspheres.

[0041] In some embodiments, the density of the separation particles 3 is between 1.05 g / cm 3 and 1.09 g / cm 3 .

[0042] It can be understood that when the density of the separation particles 3 is less than 1.05 g / cm 3 , the density of the separation particles 3 is too low, it is difficult to ensure that the bacteria in the sample collide sufficiently, and part of the bacteria can not move directionally to the inner wall surface of the separation flow channel 11; when the density of the separation particles 3 is greater than 1.09 g / cm 3 , the density of the separation particles 3 is too large, which can affect the movement of the bacteria, and the bacteria can not move to the inner wall surface of the separation flow channel 11. Therefore, the density of the separation particles 3 is set to be between 1.05 g / cm 3 and 1.09 g / cm 3 , so that the separation particles 3 can collide with the bacteria in the sample sufficiently, and at the same time, the movement of the bacteria is not affected, so that the bacteria can move directionally to the inner wall surface of the separation flow channel 11.

[0043] In some examples, the density of the separation particles 3 is, for example, 1.05 g / cm 3 or 1.09 g / cm 3 .

[0044] In some embodiments, the concentration of the separation particles 3 is between 3.5 x 10 12 / L and 5.5 x 10 12 / L.

[0045] It can be understood that when the density of the separation particles 3 is less than 3.5 x 10 12 / L, the density of the separation particles 3 is too low, it is difficult to ensure that the bacteria in the sample collide sufficiently, and part of the bacteria can not move directionally to the inner wall surface of the separation flow channel 11; when the density of the separation particles 3 is greater than 5.5 x 10 12 / L, the density of the separation particles 3 is too large, which can affect the movement of the bacteria, and the bacteria can not move to the inner wall surface of the separation flow channel 11. Therefore, the density of the separation particles 3 is set to be between 3.5 x 10 12 / L and 5.5 x 10 12 / L, so that the separation particles 3 can collide with the bacteria in the sample sufficiently, and at the same time, the movement of the bacteria is not affected, so that the bacteria can move directionally to the inner wall surface of the separation flow channel 11.

[0046] In some embodiments, the size of the separation particles 3 is between 6 μm and 8 μm.

[0047] It can be understood that the size of red blood cells in blood is about 7pm, and therefore the size of the separation particles 3 is set to be between 6pm and 8pm, so that the separation particles 3 in the shearing fluid can be similar to the red blood cells in the blood, ensuring that the separation particles 3 in the shearing fluid can effectively collide with the bacteria to make the bacteria move to the inner wall of the separation flow channel 11.

[0048] In some embodiments, referring to Figure 1 , the magnetic component 2 includes an immune magnetic bead chain 21, one end of the immune magnetic bead chain 21 is connected to the inner side wall of the separation flow channel 11, and the other end of the immune magnetic bead chain 21 extends to the center of the separation flow channel 11.

[0049] It can be understood that the immune magnetic bead chain 21 is arranged at the inner side wall of the separation flow channel 11, and the bacteria in the sample will flow to the inner side wall of the separation flow channel 11 under the action of the shearing fluid and the separation particles 3, so that the immune magnetic bead chain 21 can capture the bacteria.

[0050] It can be understood that the immune magnetic bead chain 21 is a chain structure collection of modified ferroferric oxide or iron oxide or other ferromagnetic particles with antibodies or aptamers or other recognition factors that can specifically recognize target bacteria under the action of a strong magnetic field.

[0051] In some embodiments, referring to Figure 1 , the magnetic component 2 includes at least two immune magnetic bead chains 21, the at least two immune magnetic bead chains 21 include a first immune magnetic bead chain and a second immune magnetic bead chain, and the first immune magnetic bead chain and the second immune magnetic bead chain are oppositely arranged.

[0052] It can be understood that the separation flow channel 11 includes oppositely arranged first and second inner side walls, one end of the first immune magnetic bead chain is connected to the first inner side wall, one end of the second immune magnetic bead chain is connected to the second inner side wall, and the other end of the first immune magnetic bead chain and the other end of the second immune magnetic bead chain are oppositely arranged. The first immune magnetic bead chain and the second immune magnetic bead chain can simultaneously capture bacteria, increase the capture area of the bacteria, and ensure the separation effect of the bacteria.

[0053] In some examples, the other end of the first immune magnetic bead chain abuts against the other end of the second immune magnetic bead chain to improve the capture effect of the bacteria in the separation flow channel 11.

[0054] In some embodiments, the number of the first immune magnetic bead chains is a plurality, the number of the second immune magnetic bead chains is a plurality, the plurality of first immune magnetic bead chains are arranged side by side, and the plurality of second immune magnetic bead chains are arranged side by side.

[0055] It can be understood that the plurality of first immunomagnetic bead chains are arranged side by side to form an immunomagnetic bead chain 21 group, and the plurality of second immunomagnetic bead chains are arranged side by side to form an immunomagnetic bead chain 21 group, thereby effectively improving the capture effect of bacteria.

[0056] In some embodiments, the at least two immunomagnetic bead chains 21 are uniformly distributed along the circumference of the separation flow channel 11, thereby forming a bacteria capture area along the inner wall surface of the separation flow channel 11 to achieve effective capture of bacteria in the separation flow channel 11.

[0057] In some embodiments, the first immunomagnetic bead chain magnetic component 2 further comprises a ferromagnetic substance 22 and a magnet 23, the ferromagnetic substance 22 is arranged on the outer side wall of the chip body 1, and the magnet 23 is connected to the side of the ferromagnetic substance 22 away from the chip body 1. The ferromagnetic substance 22 and the magnet 23 are used to construct a high gradient magnetic field, and the immunomagnetic bead chain 21 is located in the high gradient magnetic field.

[0058] It can be understood that the ferromagnetic substance 22 and the magnet 23 are used to construct a high gradient magnetic field, so that the immunomagnetic bead chain 21 is in the high gradient magnetic field, and the immunomagnetic beads will form a chain in the high gradient magnetic field, thereby ensuring the capture effect of bacteria in the shear fluid.

[0059] In some embodiments, the magnetic component 2 further comprises a magnetic bead plate, the magnetic bead plate is arranged on the inner side wall of the separation flow channel 11, the magnetic bead plate extends along the length direction of the inner side wall of the separation flow channel 11, and the magnetic bead plate is detachably connected to the chip body 1.

[0060] It can be understood that the magnetic bead plate can capture bacteria in the shear fluid. During the flow of the sample, the magnetic bead plate and the immunomagnetic bead chain 21 can continuously capture bacteria, thereby achieving double capture of bacteria and improving the bacteria separation effect.

[0061] In some examples, the magnetic bead plate extends along the length direction of the separation flow channel 11, and the shear fluid flows along the direction from the immunomagnetic bead chain 21 to the magnetic bead plate, that is, the immunomagnetic bead chain 21 can capture bacteria in the sample first, and then the magnetic bead plate can capture the bacteria in the sample again to improve the bacteria separation effect.

[0062] The immunomagnetic bead chain 21 is arranged before the magnetic bead plate, and the other end of the immunomagnetic bead chain 21 extends to the center of the separation flow channel 11, that is, the immunomagnetic bead chain 21 can capture bacteria that have not moved to the inner wall surface of the separation flow channel 11. As the shear fluid flows, when the bacteria flow to the position corresponding to the magnetic bead plate, the bacteria have basically moved to the inner wall surface of the separation flow channel 11, and the magnetic bead plate can effectively capture the bacteria.

[0063] In some embodiments, the first end of the first immunomagnetic bead chain chip body 1 is formed with an inlet 12 communicating with the separation flow channel 11, and the second end of the chip body 1 is formed with an outlet 13 communicating with the separation flow channel 11, so as to facilitate injection of the shearing fluid and the sample into the separation flow channel 11, so that the shearing fluid and the sample can flow in the direction from the inlet 12 to the outlet 13.

[0064] In some embodiments, the bacterial separation chip further comprises a first fluid pump connected with the inlet 12 to deliver fluid into the separation flow channel 11.

[0065] It can be understood that the shearing fluid and the sample can be delivered into the separation flow channel 11 by the first fluid pump, and can flow in the separation flow channel 11.

[0066] In some embodiments, the bacterial separation chip further comprises a second fluid pump connected with the outlet 13, and the first fluid pump and the second fluid pump are used to drive the fluid in the separation flow channel 11 to flow reciprocally.

[0067] It can be understood that the first fluid pump can drive the shearing fluid and the sample in the separation flow channel 11 to flow in the direction from the inlet 12 to the outlet 13, and the second fluid pump can drive the shearing fluid and the sample in the separation flow channel 11 to flow in the direction from the outlet 13 to the inlet 12. When the separation effect of bacteria is insufficient, the shearing fluid and the sample can be repeatedly flowed in the separation flow channel 11 by the first fluid pump and the second fluid pump, so as to improve the separation effect of bacteria.

[0068] According to a second aspect of the present application, referring to Figure 2 , the present disclosure provides a bacterial separation method. The bacterial separation method comprises:

[0069] Step 101, injecting a shearing fluid into the separation flow channel 11 of the chip body 1 to form a shearing flow field in the separation flow channel 11;

[0070] Step 102, arranging the immunomagnetic bead chain 21 on the inner side wall of the separation flow channel 11, and constructing a high-gradient magnetic field at the chip body 1 to make the immunomagnetic bead chain 21 located in the high-gradient magnetic field;

[0071] Step 103, mixing a sample to be separated with the separation particles 3 to obtain a mixed sample;

[0072] Step 104, injecting the mixed sample into the separation flow channel 11, so that the bacteria in the mixed sample flow to the edge of the separation flow channel 11 under the action of the shearing fluid and the separation particles 3.

[0073] It can be understood that the separation flow channel 11 is a high-speed flow field, and the separation flow channel 11 is filled with a shearing fluid. A high-gradient magnetic field is constructed at the chip body 1, and the immunomagnetic bead chain 21 will form a chain in the high-gradient magnetic field, so that the immunomagnetic bead chain 21 can capture bacteria.

[0074] The target bacteria in the sample to be separated are mixed with the separation particles 3 and then continuously introduced into the separation flow channel 11, and the flow rate is controlled. Under the action of the separation particles 3 and the shearing fluid, the target bacteria gradually move to the two side edges in the normal direction, so that the target bacteria flow to the inner side wall of the separation flow channel 11, and are captured by the immunomagnetic bead chain 21, thereby realizing rapid separation of the target bacteria in the moving process of the sample to be separated.

[0075] In some examples, the target bacteria are, for example, common Escherichia coli, Salmonella and other bacteria with a diameter of 1-2 μm.

[0076] In some examples, a shearing fluid is provided in the separation flow channel 11 to form a shearing flow field. In order to simulate the shearing flow field condition in which the platelets in the blood are easy to adhere, the shear rate (γ) in the shearing flow field is 20 s -1 to 5000 s -1 .

[0077] Specifically, Q = 2πR4v max (1);

[0078] where Q is the flow rate in the shearing flow field, R is the radius of the shearing flow field, and v max is the maximum flow rate in the shearing flow field;

[0079] The relationship between the maximum shear rate and the maximum flow rate is: γ = 2v max / R (2);

[0080] Substituting equation (2) into equation (1), Q = 4πR5γ (3) is obtained.

[0081] Taking a pipe with a radius of 5 mm as an example, Q = 0.007~1.97 mL / s = 0.47~118 mL / min.

[0082] In the description of the present application, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0083] In the above embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0084] The embodiments, implementation manners and related technical features of the present application can be combined or replaced with each other without conflict.

[0085] The above is only the preferred embodiments of the present application, and does not limit the present application in any form. Any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application without departing from the technical solution content of the present application still falls within the scope of the technical solution of the present application.

Claims

1. A bacterial separation chip, characterized in that: The diameter of the bacteria is 1-2 μm, and the bacteria separation chip comprises: A chip body, wherein the chip body is formed with a separation flow channel, and the separation flow channel is used to accommodate a sample; a magnetic component connected to the chip body, at least a portion of the magnetic component being located within the separation flow channel and on an inner wall surface of the separation flow channel, and the magnetic component being used to capture bacteria in a sample; A shear fluid is provided in the separation channel, and separation particles are provided in the sample, so that bacteria in the sample move toward the inner wall surface of the separation channel under the action of the shear fluid and the separation particles; The shear fluid is a biocompatible liquid; The magnetic component includes an immunomagnetic bead chain, one end of the immunomagnetic bead chain is connected to the inner wall of the separation channel, and the other end of the immunomagnetic bead chain extends toward the center of the separation channel; wherein, The density of the separated particles is 1.05 g / cm 3 to 1.09g / cm 3 between; and / or, The concentration of the separated particles was 3.5×10 12 pcs / L to 5.5×10 12 Between 1 / L; and / or, The size of the separated particles is between 6 μm and 8 μm.

2. The bacterial isolation chip according to claim 1, characterized in that The separation particles are polystyrene microspheres.

3. The bacteria separation chip according to claim 1, characterized in that The magnetic component includes at least two immunomagnetic bead chains, and the at least two immunomagnetic bead chains include a first immunomagnetic bead chain and a second immunomagnetic bead chain, and the first immunomagnetic bead chain and the second immunomagnetic bead chain are arranged opposite to each other.

4. The bacteria separation chip according to claim 3, characterized in that There are multiple first immunomagnetic bead chains, and there are multiple second immunomagnetic bead chains. Multiple first immunomagnetic bead chains are arranged side by side, and multiple second immunomagnetic bead chains are arranged side by side.

5. The bacteria separation chip according to claim 1, characterized in that The magnetic component also includes ferromagnetic material and a magnet. The ferromagnetic material is arranged on the outer wall of the chip body, and the magnet is connected to the side of the ferromagnetic material facing away from the chip body. The ferromagnetic material and the magnet are used to construct a high-gradient magnetic field, and the immunomagnetic bead chain is located in the high-gradient magnetic field.

6. The bacteria separation chip according to any one of claims 1 to 5, characterized in that: An inlet communicating with the separation channel is formed at a first end of the chip body, and an outlet communicating with the separation channel is formed at a second end of the chip body.

7. A bacteria separation method based on the bacteria separation chip according to any one of claims 1 to 6, characterized in that: include: injecting a shear fluid into the separation flow channel of the chip body to form a shear flow field in the separation flow channel; Arranging the immunomagnetic bead chain on the inner side wall of the separation channel, and constructing a high gradient magnetic field at the chip body so that the immunomagnetic bead chain is located in the high gradient magnetic field; mixing the sample to be separated with the separation particles to obtain a mixed sample; The mixed sample is injected into the separation channel, so that the bacteria in the mixed sample flow toward the edge of the separation channel under the action of the shear fluid and the separation particles.

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