A whole blood plasma separation device and method combining filter membrane and magnetic beads

Abstract

The present invention discloses a whole blood plasma separation device combining a filter membrane and magnetic beads, comprising a sample suction needle module, a sample addition needle module, a vacuum module, a photoelectric detection module, a separation cup and a rotating disk mechanism; the separation cup comprises a cup body, a filter membrane assembly arranged in the cup body and a reactant arranged at the bottom of the cup body; the reactant comprises freeze-dried immunomagnetic beads and antibody reagents; the rotating disk mechanism comprises a fixed base, a rotating shaft arranged at the center of the fixed base and a separation cup tray located above the fixed base and rotating with the rotating shaft. The present invention also provides a whole blood plasma separation method. The device provided by the present invention can effectively solve the problem that plasma is difficult to separate when the hematocrit of clinical whole blood samples is high, and meet the requirements of in vitro diagnostic multi-item detection for the pre-treatment amount of whole blood samples.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a whole blood plasma separation device and method combining a filter membrane with magnetic beads. Background Art

[0002] When IVD (In Vitro Diagnostics) uses blood samples to obtain clinical diagnostic information, it is usually pre-treated to separate plasma / serum from whole blood samples before testing. If whole blood samples are used directly for testing, the blood cells in them will interfere with the analysis process and affect the accuracy of the test results. At present, the more mature whole blood separation method is to use special centrifugal equipment to separate plasma / serum, with a relative centrifugal force RCF of 1000~1200g and a centrifugation time of 5~10 minutes. The problem is that the centrifugal equipment is large and difficult to integrate with small and medium-sized testing equipment and realize automation; the centrifugation time is long, which is difficult to meet the growing clinical demand for rapid testing. The filtration separation method uses filter membranes, microcolumns, microspheres, etc. to capture or intercept blood cells and separate plasma / serum; the immunomagnetic bead separation method uses magnetic beads labeled with antibodies to bind to blood cell antigens in whole blood samples to separate plasma / serum. Compared with the centrifugal separation method, the above two methods have the advantages of good separation quality, high efficiency, simple operation, and easy automation, and are particularly suitable for point-of-care testing (POCT) applications. However, faced with the increase in whole blood sample size due to the demand for blood volume for multiple clinical tests and the high hematocrit (50%-60%) in clinical whole blood samples, the current single filtration separation method or immunomagnetic bead separation method has technical bottlenecks, and how to improve separation efficiency and reduce usage costs faces challenges.

[0003] Patent document CN110857904A discloses a method for obtaining plasma from a whole blood sample, a blood filter and a microfluidic chip, wherein the blood filter includes a coarse filtration module and a purification module, wherein the coarse filtration module includes a first filter cup and a filter element, wherein the filter element is preferably an acetate fiber column, and the purification module includes a second filter cup, an annular press and a filter membrane, wherein the filter membrane is a Pall Vivid GR plasma separation membrane. The filtration speed of this method is slow, and when there are too many filter membrane layers or the filter membrane is overloaded and blocked, it is difficult to filter out plasma, resulting in low plasma recovery efficiency, and it is unable to meet the blood volume requirements for multi-item testing.

[0004] Patent document CN117625529A discloses an immunomagnetic bead freeze-dried microsphere for separating red blood cells, and its preparation method, application and blood processing device, the device includes a blood collection test tube and an immunomagnetic bead freeze-dried microsphere built into the test tube, the blood collection test tube is fixed by a bracket, a magnet is installed in the bracket, and the magnet is located directly below the test tube. In order to obtain a faster separation speed, the device uses a larger amount of magnetic beads. The amount of magnetic beads used to process 100uL of whole blood sample is as high as 30mg, and as the amount of whole blood sample increases, the immunomagnetic bead freeze-dried microsphere is increased proportionally, resulting in a longer separation time. When the blood volume required for multi-item testing is large, the use cost and separation efficiency of the device cannot be met. In addition, the device is manually operated, which is difficult to meet the requirements of online inspection automation integration. Summary of the invention

[0005] The purpose of the present invention is to provide a whole blood plasma separation device and method combining a filter membrane and magnetic beads, which can effectively solve the problem that plasma is difficult to separate when the hematocrit of clinical whole blood samples is high, and meet the requirements of in vitro diagnostic multi-item testing for the pre-treatment volume of whole blood samples.

[0006] In order to achieve the first object of the present invention, the following technical scheme is provided: a whole blood plasma separation device combining a filter membrane and magnetic beads, comprising a sample suction needle module, a sample addition needle module, a vacuum module, a photoelectric detection module, a separation cup and a rotating disk mechanism;

[0007] The separation cup comprises a cup body, a filter membrane assembly arranged in the cup body and a reactant arranged at the bottom of the cup body, the cup body is divided into an inlet section and a reaction section, the inlet section has a diameter larger than the reaction section to form a limiting boss at the connection part, the filter membrane assembly comprises a hollow tube, a filter membrane support plate arranged along the outer circumference of the hollow tube, a filter membrane arranged on the filter membrane support plate, and a filter membrane pressing plate sleeved on the hollow tube for fixing the filter membrane, the filter membrane pressing plate and the filter membrane support plate are correspondingly provided with a connecting hole for connecting the inlet section and the reaction section, and the filter membrane support plate and the limiting boss are adapted to separate the inlet section and the reaction section, and an injection cavity for a whole blood sample is formed between the hollow tube and the inlet section of the cup body;

[0008] The reactants include freeze-dried immunomagnetic beads and antibody reagents;

[0009] The rotating disk mechanism includes a fixed base, a rotating shaft arranged at the center of the fixed base, and a separation cup tray located above the fixed base and rotating with the rotating shaft, the separation cup tray is provided with placement holes for fixing the separation cup, the top surface of the fixed base forms mounting holes in a circular array along the circumference, a portion of adjacent mounting holes are provided with magnetic absorption modules for adsorbing immune magnetic beads, and another portion of adjacent mounting holes are provided with oscillation mixing modules for promoting the immune reaction rate in the separation cup;

[0010] The sample injection needle module is used to inject the whole blood sample into the injection chamber;

[0011] The vacuum module performs vacuum treatment on the reaction section by connecting the hollow tube;

[0012] The sample aspirating needle module is used to extract the plasma sample obtained by the reaction through the hollow tube and transfer the plasma sample to the sample cup;

[0013] The photoelectric detection module is used to detect the plasma sample in the sample cup.

[0014] The present invention separates plasma from a whole blood sample by combining a filtration separation method and an immunomagnetic bead separation method. First, a filter membrane is used to intercept some blood cells in the whole blood sample, and then freeze-dried immunomagnetic beads and antibody reagents are used to capture the remaining blood cells in the whole blood sample, thereby effectively improving the whole blood sample processing capacity and enhancing the plasma separation efficiency and separation quality.

[0015] Specifically, the inlet section of the cup body is also provided with a sealing film.

[0016] Specifically, the filter membrane has multiple layers, and a stainless steel filter mesh is arranged between two adjacent layers of the filter membrane.

[0017] Specifically, the filter membrane is a polyethersulfone filter membrane, and the pore size of the filter membrane is 3 to 5 microns.

[0018] Specifically, the vacuum tube is provided with a funnel head with a gradually increasing opening at one end of the reaction section.

[0019] Specifically, the oscillation and mixing module includes a motor, a rotating paddle, a sensor switch and a sensor sheet. The rotation axis of the rotating paddle is parallel to the central axis of the corresponding placement hole above and deviates by 1 to 2 mm.

[0020] Specifically, the magnetic attraction module arranges the magnets in a Halbach ring array.

[0021] In order to achieve the second object of the present invention, the following technical solution is provided: a method for separating plasma from whole blood, which is implemented by the whole blood plasma separation device combining the above-mentioned filter membrane with magnetic beads, comprising the following steps:

[0022] Step 1: Place the separation cup containing freeze-dried immune magnetic beads and antibody reagents into the placement hole of the separation cup tray, and rotate the rotating disk to move the separation cup to the sample loading position;

[0023] Step 2: The sample adding needle module draws a quantitative whole blood sample and adds it into the injection cavity of the separation cup. The rotating disk rotates to move the separation cup to the vacuum position. The vacuum needle is inserted into the hollow tube of the separation cup, and the vacuum pump is started to vacuum the reaction section of the separation cup.

[0024] Step 3: After the filtration is completed, the vacuum pump is stopped and the vacuum needle is removed. The motor of the oscillation and mixing module drives the rotating paddle to rotate, and the lower part of the separation cup is shaken. The filtered whole blood sample is fully mixed with the freeze-dried immune magnetic beads and antibody reagents in the separation cup to carry out an immune reaction;

[0025] Step 4: After the immune reaction is completed, the separation cup is taken out and placed in the center of the magnetic absorption module, so that the immune magnetic beads after the reaction are evenly adsorbed on the inner wall of the separation cup;

[0026] Step 5: After the magnetic separation is completed, the rotating disk rotates to move the separation cup to the sample suction position, and the sample suction needle is inserted into the hollow tube of the separation cup to suck the separated plasma sample into the sample cup;

[0027] Step 6: The photoelectric detection module tests the separated plasma sample in the sample cup and evaluates the separated plasma sample according to a preset algorithm.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The separation cup cleverly integrates the functions of vacuum filtration and immunomagnetic bead separation. Under the action of negative pressure, the whole blood sample passes through the filter membrane and enters the lower cavity of the cup body, reacts with the pre-stored freeze-dried immunomagnetic beads and antibody reagents, and magnetically separates the plasma sample.

[0030] By setting up a rotating disk, functional modules such as adding whole blood, vacuuming, oscillating and mixing, magnetic separation, and plasma aspiration are integrated. The rotation of the rotating disk can bring the separation cup to each operating position to complete the corresponding function. The operation is simple and the integration is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of the structure of the whole blood plasma separation device provided in this embodiment;

[0032] Figure 2 A schematic diagram of a driving mechanism provided in this embodiment;

[0033] Figure 3 A schematic diagram of a rotating disk mechanism provided for this embodiment;

[0034] Figure 4 A schematic diagram of the structure of the separation cup provided in this embodiment;

[0035] Figure 5 A cross-sectional view of the cup body provided in this embodiment;

[0036] Figure 6 A schematic diagram of the structure of the filter membrane assembly provided in this embodiment;

[0037] Figure 7A schematic diagram of the hollow tube and the filter membrane support plate provided in this embodiment;

[0038] Figure 8 A schematic diagram of a filter membrane pressing plate provided in this embodiment;

[0039] In the figure, 1, sample suction needle module; 2, sample suction needle; 3, vacuum needle; 4, vacuum module; 5, sample cup; 6, sample cup holder; 7, photoelectric detection module; 8, separation cup; 9, magnetic absorption module; 10, oscillation mixing module; 11, turntable mechanism; 12, sample addition needle; 13, sample addition needle module; 14, first sample control pump valve; 15, second sample control pump valve; 16, second X-axis moving module; 17, second Z-axis moving module; 18, first X-axis moving module; 19, first Z-axis moving module; 20, Lifting module; 21. Fixed base; 22. Motor; 23. Rotating paddle; 24. Induction sheet; 25. Induction switch; 26. Separation cup tray; 27. Sealing film; 28. Filter membrane assembly; 29. ​​Cup body; 30 Reactant; 31. First groove; 32. Second groove; 33. Boss; 34. Filter membrane; 35. Filter membrane pressing plate; 36. Filter membrane supporting plate; 37. Second protrusion; 38. Hollow tube; 39. Connecting hole; 40. First protrusion; 41. Funnel mouth; 42. Third groove; 43. Third protrusion. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0041] like Figure 1 and Figure 2 As shown, a whole blood plasma separation device combining a filter membrane and magnetic beads is provided in this embodiment, which includes a separation cup 8, a sample adding needle module 13, a vacuum module 4, an oscillation mixing module 10, a magnetic absorption module 9, a turntable mechanism 11, a sample absorption needle module 1 and a photoelectric detection module 7.

[0042] The sample adding needle module 13 , the vacuum pumping module 4 and the sample aspirating needle module 1 are arranged around the turntable mechanism 11 , and correspond to fixed sample adding positions, vacuum pumping positions and sample aspirating positions respectively.

[0043] The oscillation and mixing module 10 and the magnetic attraction module 9 are arranged on the turntable mechanism 11 .

[0044] like Figure 3 As shown, the separation cup 8 can be placed on the separation cup tray 26 of the oscillation and mixing module 10 , or can be placed in the center of the annular magnet of the magnetic attraction module 9 .

[0045] The sample adding needle module 13 includes a sample adding needle 12, a first X-axis moving module 18, a first Z-axis moving module 19, a first sample control pump valve 14, and a matching first needle cleaning unit. The sample adding needle 12 is used to quantitatively draw a whole blood sample and add it to the separation cup 8. The sample adding needle 12 is fixedly connected to the slider of the first Z-axis moving module 19, and the first Z-axis moving module 19 is fixedly connected to the slider of the first X-axis moving module 18. The first Z-axis moving module 19 is used to control the up and down movement of the sample adding needle 12. The first X-axis moving module 18 is used to control the left and right movement of the sample adding needle 12. The first sample control pump valve 14 is connected to the top of the sample adding needle 12 through a pipeline, and is used to control the amount of sample sucked in and discharged by the sample adding needle 12. The first needle cleaning unit is used to clean the inner and outer walls of the sample adding needle 12 to prevent cross contamination between different samples.

[0046] The vacuum module 4 includes a vacuum needle 3, a seal, a lifting module 20, and a vacuum pump. The vacuum needle 3 is fixed on the lifting module 20, and driven by the lifting module 20, the vacuum needle 3 can be inserted into the separation cup 8. The vacuum pump is connected to the top of the vacuum needle 3 through a pipeline, and is used to perform a vacuum operation on the reaction section of the separation cup.

[0047] The oscillation mixing module 10 includes a motor 22, a rotating paddle 23, a sensor switch 25, and a sensor sheet 24. The motor 22 is fixed on the fixed base 21, the motor shaft of the motor 22 is fixedly connected to the rotating paddle 23, the sensor sheet 24 is fixedly connected to the rotating paddle 23, and the sensor switch 25 is fixed on the fixed base 21. The motor 22 drives the rotating paddle 23 to rotate, and the stop position of the rotating paddle 23 is controlled by the sensor switch 25 and the sensor sheet 24. The separation cup tray 26 is fixed on the fixed base 21 and is located above the rotating paddle 23. A placement hole is provided on the separation cup tray 26, and the diameter of the placement hole is slightly larger than the outer diameter of the lower part of the separation cup 8 and smaller than the outer diameter of the upper part of the separation cup 8, so that the separation cup 8 can smoothly fall into the placement hole of the separation cup tray 26, and is suspended on the separation cup tray 26 by the flange between the upper and lower parts of the separation cup 8. The axis of the hole of the separation cup tray 26 is parallel to the axis of the rotating paddle 23 and deviates from it by a certain distance, so that the distance between the paddle and the wall of the separation cup 8 changes continuously during the rotation of the rotating paddle 23, thereby shaking the lower part of the separation cup 8 to achieve the effect of oscillation and mixing.

[0048] The magnetic absorption module 9 is used to absorb the immunomagnetic beads after the reaction is completed to the inner wall of the separation cup 8. The magnetic absorption module 9 arranges the magnets in a Halbach ring array.

[0049] The fixed base 21 is provided with a plurality of evenly distributed oscillating and mixing modules 10 and a plurality of evenly distributed magnetic attraction modules 9, which can perform oscillating and mixing operations and magnetic attraction and separation operations simultaneously.

[0050] The separation cup 8 can be switched to the sample adding position, the vacuuming position and the sample sucking position in sequence by the rotation of the separation cup tray 26 .

[0051] The sample suction needle module 1 includes a sample suction needle 2, a second X-axis moving module 16, a second Z-axis moving module 17, a second sample control pump valve 15, and a second needle cleaning unit. The sample suction needle 2 is used to quantitatively aspirate the separated plasma sample. The sample suction needle 2 is fixedly connected to the slider of the second Z-axis moving module 17, and the second Z-axis moving module 17 is fixedly connected to the slider of the second X-axis moving module 16. The second Z-axis moving module 17 is used to control the up and down movement of the sample suction needle 2. The second X-axis moving module 16 is used to control the left and right movement of the sample suction needle 2. The second sample control pump valve 15 is connected to the top of the sample suction needle 2 through a pipeline, and is used to control the amount of sample sucked and discharged by the sample suction needle. The second needle cleaning unit is used to clean the inner and outer walls of the sample suction needle 2 to prevent cross contamination between different samples.

[0052] The photoelectric detection module 7 includes a sample cup 5, a sample cup holder 6, a light source and a photon receiver. The sample cup 5 is used to store the separated plasma sample and should be made of a transparent material. The sample cup holder 6 is provided with a hole for placing the sample cup 5. A window is provided on the sample cup holder 6 at a position opposite to the sample cup 5, and the light source and the photon receiver detect the plasma sample in the sample cup 5 through the window. Different wavelength light sources are used to act on the plasma sample in a transmission or reflection manner, and a silicon photocell or a photomultiplier tube is used to receive the returned photons. Blood cells may remain in the separated plasma sample or hemolysis may occur. Plasma samples in different states have different light absorption and scatter coefficients. The separated plasma sample is classified or graded according to the number or intensity of the returned photons received by the silicon photocell or the photomultiplier tube. The classification or grading method can be based on a threshold method, or on a machine learning algorithm such as a random forest, a support vector machine, or Bayes. The results of the classification or grading can be fed back to the remote end for further analysis and control.

[0053] like Figure 4 As shown, the separation cup provided in this embodiment includes a cup body 29 for pre-storing reactants 30, a filter membrane assembly 28 and a sealing membrane 27. The reactants 30 mentioned in this embodiment are freeze-dried immunomagnetic beads and antibody reagents.

[0054] like Figure 5As shown, a boss and a groove are provided in the cup body 29 . The boss is used to support the filter membrane assembly 28 , and the groove cooperates with the protrusion on the filter membrane assembly 28 to fix the filter membrane assembly 28 and the cup body 29 .

[0055] The reaction section of the cup body stores freeze-dried immunomagnetic beads and antibody reagents in advance, and serves as a chamber for oscillating and mixing the filtered whole blood sample with the freeze-dried immunomagnetic beads and antibody reagents, generating immune reactions, and magnetic separation.

[0056] like Figure 6 As shown, the filter membrane assembly 28 includes a filter membrane 34, a filter membrane support plate 36, a filter membrane pressing plate 35 and a sealing member. The filter membrane 34 is placed above the filter membrane support plate 36, the sealing member is placed above the filter membrane 34, and the filter membrane pressing plate 35 is placed above the sealing member. After the filter membrane pressing plate 35 is fixedly connected to the filter membrane support plate 36, the sealing member and the filter membrane 34 are pressed tightly between the two.

[0057] In this embodiment, the filter membrane 34 is a single layer or two layers are stacked, and the two layers of stacked filter membranes are separated by a stainless steel filter mesh. The filter membrane material is preferably a PES (polyethersulfone) filter membrane, and the pore size of the filter membrane is preferably 3-5 microns.

[0058] Both the filter membrane support plate 36 and the filter membrane pressing plate 35 are provided with connecting holes 39, which are beneficial to increase the effective area of ​​the filter membrane and improve the filtering effect of the whole blood sample.

[0059] like Figure 7 As shown, the outer ring of the filter membrane support plate 36 is provided with a first protrusion 40 for cooperating with the first groove 31 of the inlet section of the cup body 29 to play a role of fixed connection with the cup body 29 .

[0060] A hollow tube 38 is provided in the center of the filter membrane support plate 36, which runs through the top and bottom. The hollow tube 38 has two functions. First, during the whole blood sample filtering process, a vacuum needle is inserted from the hollow tube 38 and connected to a vacuum pump to vacuum the cavity of the reaction section of the cup body 29, so that a pressure difference is formed on both sides of the filter membrane 34, which helps to accelerate the whole blood sample filtering process; second, after the filtered whole blood sample is subjected to a series of operations such as oscillation mixing, immune reaction and magnetic separation with the freeze-dried immune magnetic beads and antibody reagents, a sample suction needle is inserted from the hollow tube 38 and connected to the sample suction pump 1 to suck out the separated plasma sample from the reaction section of the cup body 29.

[0061] The lower end of the hollow tube 38 is provided with a funnel 41 to guide the filtered whole blood sample, which can effectively prevent the whole blood sample from being sucked into the hollow tube 38 during the vacuum operation.

[0062] A second protrusion 37 is provided in the middle of the hollow tube 38 for cooperating with the third groove 42 of the inner circle of the filter membrane pressing plate 35 to play a role of fixed connection with the filter membrane pressing plate 35 .

[0063] like Figure 8 As shown, the outer ring of the filter membrane pressing plate 35 is provided with a third protrusion 43 for cooperating with the groove 2 on the upper part of the cup body to play the role of fixed connection with the cup body.

[0064] A through hole is provided in the center of the membrane pressing plate 35 for being sleeved with the hollow tube 38 of the membrane supporting plate 36 ; a third groove 42 is provided on the inner wall of the through hole for cooperating with the second protrusion 37 on the membrane supporting hollow tube to play a role in fixing the connection with the membrane supporting plate 36 .

[0065] This embodiment also provides a method for separating plasma from whole blood, which is implemented by a whole blood plasma separation device combining a filter membrane and magnetic beads provided in the above embodiment, and the steps include:

[0066] Step 1: Place the separation cup containing freeze-dried immunomagnetic beads and antibody reagents into the circular hole of the separation cup tray of the oscillating mixing module, and rotate the rotating disk to move the separation cup to the sample loading position.

[0067] Step 2: The sample adding needle module draws a quantitative whole blood sample and adds it to the top of the filter membrane assembly of the separation cup. The rotating disk rotates to move the separation cup to the vacuum position. The vacuum needle is inserted into the hollow tube of the separation cup. The vacuum pump is started to vacuum the lower cavity of the separation cup. The whole blood sample passes through the filter membrane under the action of the pressure difference, and some blood cells are intercepted above the filter membrane.

[0068] Step 3: After the filtration is completed, the vacuum pump is stopped and the vacuum needle is removed. The motor of the oscillation and mixing module drives the rotating paddle to rotate, and the lower part of the separation cup is shaken. The filtered whole blood sample is fully mixed with the freeze-dried immune magnetic beads and antibody reagents in the separation cup to carry out an immune reaction;

[0069] Step 4: After the immune reaction is completed, take out the separation cup and put it into the center of the ring magnet of the magnetic absorption module. Under the action of the magnetic field, the immune magnetic beads after the reaction are evenly adsorbed on the inner wall of the separation cup.

[0070] Step 5: After the magnetic separation is completed, the rotating disk rotates to move the separation cup to the sample suction position, and the sample suction needle is inserted into the hollow tube of the separation cup to suck the quantitatively separated plasma sample into the sample cup.

[0071] Step 6: The photoelectric detection module tests the separated plasma sample in the sample cup and evaluates the separated plasma sample according to a preset algorithm.

[0072] In order to further illustrate the technical effect of the solution provided in this embodiment, relevant comparative experiments were conducted to improve the recovery efficiency, recovery quality and use cost of whole blood separated plasma.

[0073] The following is the experimental data of whole blood samples with high hematocrit (HCT=60%). The whole blood samples used in the comparison experiment are consistent. The specific results are as follows:

[0074] The separation cup for separating whole blood from plasma is completed by combining the filter membrane and magnetic beads provided in this embodiment, wherein the filter membrane is a layer of PES filter membrane, the filter membrane diameter is 10.5mm (the middle pore diameter is 4mm), the filter membrane pore diameter is 5μm, and the amount of magnetic beads is 1mg. After adding 700μL of whole blood sample, the amount of sample entering the lower part of the cup body after vacuum filtration is about 600μL, the hematocrit is reduced (HCT is about 50%), and the amount of blood cells intercepted is about 30%. In the comparative experiment, the amount of magnetic beads used in the magnetic bead separation method is 1mg; the filter membrane used in the filtration separation method is a combination of two layers of glass fiber filter membrane and two layers of polysulfone membrane, and the filter membrane diameter is 20mm.

[0075] The comparative test results of the three separation methods are shown in Table 1.

[0076] .

[0077] Under the same dosage of magnetic beads, the interception effect of the filter membrane reduces the hematocrit of the whole blood sample, and the parameters such as plasma recovery and separation time are significantly improved during the further magnetic bead separation process. In the filtration separation method, the filter membrane is overloaded and clogged, resulting in less plasma recovery, longer separation time, and hemolysis.

[0078] In summary, the advantages of the device provided in this embodiment over the prior art are:

[0079] 1. Plasma is separated from whole blood samples by combining filtration separation method and immunomagnetic bead separation method. First, some blood cells in the whole blood sample are intercepted by filter membrane, and then the remaining blood cells in the whole blood sample are captured by freeze-dried immunomagnetic beads and antibody reagents, which effectively improves the whole blood sample processing capacity and enhances the plasma separation efficiency and quality.

[0080] 2. The separation cup cleverly integrates the functions of vacuum filtration and immunomagnetic bead separation. Under the action of negative pressure, the whole blood sample passes through the filter membrane into the lower cavity of the cup, reacts with the pre-stored freeze-dried immunomagnetic beads and antibody reagents, and magnetically separates the plasma sample.

[0081] 3. The separation device integrates functional modules such as adding whole blood, vacuuming, oscillating and mixing, magnetic separation, and plasma aspiration by setting a rotating disk. The rotating disk can bring the separation cup to each operating position to complete the corresponding function. It is easy to operate and highly integrated.

[0082] 4. The separated plasma samples are tested using a photoelectric detection method and evaluated according to a preset algorithm. The evaluation results are conducive to the correct use of the plasma samples in the next step of testing and analysis.

[0083] In addition, the terms "upper", "lower", "inner", "outer", "front", "rear" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. Unless otherwise specifically stated, the relative steps, numerical expressions and values ​​of the components and steps described in these embodiments do not limit the scope of the present invention.

[0084] Of course, the above description is only a specific embodiment of the present invention and is not intended to limit the scope of implementation of the present invention. All equivalent changes or modifications made according to the structure, characteristics and principles described in the patent application scope of the present invention should be included in the patent application scope of the present invention.

[0085] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A whole blood plasma separation device combining a filter membrane and magnetic beads, characterized in that: It includes a sample suction needle module, a sample addition needle module, a vacuum module, a photoelectric detection module, a separation cup and a rotating disk mechanism; The separation cup comprises a cup body, a filter membrane assembly arranged in the cup body and a reactant arranged at the bottom of the cup body, the cup body is divided into an inlet section and a reaction section, the inlet section has a diameter larger than the reaction section to form a limiting boss at the connection part, the filter membrane assembly comprises a hollow tube, a filter membrane support plate arranged along the outer circumference of the hollow tube, a filter membrane arranged on the filter membrane support plate, and a filter membrane pressing plate sleeved on the hollow tube for fixing the filter membrane, the filter membrane pressing plate and the filter membrane support plate are correspondingly provided with a connecting hole for connecting the inlet section and the reaction section, and the filter membrane support plate and the limiting boss are adapted to separate the inlet section and the reaction section, and an injection cavity for a whole blood sample is formed between the hollow tube and the inlet section of the cup body; The reactants include freeze-dried immunomagnetic beads and antibody reagents; The rotating disk mechanism includes a fixed base, a rotating shaft arranged at the center of the fixed base, and a separation cup tray located above the fixed base and rotating with the rotating shaft, the separation cup tray is provided with placement holes for fixing the separation cup, the top surface of the fixed base forms mounting holes in a circular array along the circumference, a portion of adjacent mounting holes are provided with magnetic absorption modules for adsorbing immune magnetic beads, and another portion of adjacent mounting holes are provided with oscillation mixing modules for promoting the immune reaction rate in the separation cup; The sample injection needle module is used to inject the whole blood sample into the injection chamber; The vacuum module performs vacuum treatment on the reaction section by connecting the hollow tube; The sample aspirating needle module is used to extract the plasma sample obtained by the reaction through the hollow tube and transfer the plasma sample to the sample cup; The photoelectric detection module is used to detect the plasma sample in the sample cup.

2. The whole blood plasma separation device combining filter membrane and magnetic beads according to claim 1, characterized in that: The inlet section of the cup body is also provided with a sealing film.

3. The whole blood plasma separation device combining filter membrane and magnetic beads according to claim 1, characterized in that: The filter membrane has multiple layers, and a stainless steel filter net is arranged between two adjacent layers of filter membrane.

4. The whole blood plasma separation device combining filter membrane and magnetic beads according to claim 1, characterized in that: The filter membrane is a polyethersulfone filter membrane, and the pore size of the filter membrane is 3 to 5 microns.

5. The whole blood plasma separation device combining filter membrane and magnetic beads according to claim 1, characterized in that: The hollow tube is provided with a funnel head with a gradually increasing opening at one end of the reaction section.

6. The whole blood plasma separation device combining filter membrane and magnetic beads according to claim 1, characterized in that: The oscillation and mixing module includes a motor, a rotating paddle, a sensor switch and a sensor sheet. The rotating axis of the rotating paddle is parallel to the central axis of the corresponding placement hole above and deviates by 1 to 2 mm.

7. The whole blood plasma separation device combining filter membrane and magnetic beads according to claim 1, characterized in that: The magnetic attraction module arranges the magnets in a Halbach ring array.

8. A method for separating plasma from whole blood, characterized in that: The method is realized by a whole blood plasma separation device combining a filter membrane and magnetic beads as described in any one of claims 1 to 7, wherein the steps include: Step 1: Place the separation cup containing freeze-dried immune magnetic beads and antibody reagents into the placement hole of the separation cup tray, and rotate the rotating disk to move the separation cup to the sample loading position; Step 2: The sample adding needle module draws a quantitative whole blood sample and adds it into the injection cavity of the separation cup. The rotating disk rotates to move the separation cup to the vacuum position. The vacuum needle is inserted into the hollow tube of the separation cup, and the vacuum pump is started to vacuum the reaction section of the separation cup. Step 3: After the filtration is completed, the vacuum pump is stopped and the vacuum needle is removed. The motor of the oscillation and mixing module drives the rotating paddle to rotate, and the lower part of the separation cup is shaken. The filtered whole blood sample is fully mixed with the freeze-dried immune magnetic beads and antibody reagents in the separation cup to carry out an immune reaction; Step 4: After the immune reaction is completed, the separation cup is taken out and placed in the center of the magnetic absorption module, so that the immune magnetic beads after the reaction are evenly adsorbed on the inner wall of the separation cup; Step 5: After the magnetic separation is completed, the rotating disk rotates to move the separation cup to the sample suction position, and the sample suction needle is inserted into the hollow tube of the separation cup to suck the separated plasma sample into the sample cup; Step 6: The photoelectric detection module tests the separated plasma sample in the sample cup and evaluates the separated plasma sample according to a preset algorithm.

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