Quantitative blood filtration chip

Abstract

The present invention relates to a quantitative blood filtration chip. Specifically, it relates to a chip including a chip body, wherein the chip body includes: a blood filtration mechanism, a liquid storage mechanism, and an indication mechanism; the liquid storage mechanism includes: a liquid storage tank and a liquid storage outlet provided at the bottom of the liquid storage tank; wherein the volume of the liquid storage tank is V 储 The top of the chip has a top opening, and the liquid storage outlet area S is small enough so that the liquid in the liquid storage tank will not flow out without external force; and at least a part of the indicator mechanism is transparent and is used to indicate whether the filtered blood in the liquid storage tank of the liquid storage mechanism has filled the liquid storage tank. The chip of the present invention has a simple structure, is easy to process and is suitable for mass production, and is easy to use, time-saving and labor-saving, and is suitable for use in combination with other chips.

Description

Technical Field

[0001] The invention belongs to the field of detection, and in particular relates to a quantitative blood filtration chip. Background Art

[0002] Microfluidic chip technology has attracted more and more attention due to its low consumption, high throughput, high integration, etc. Through different designs, microfluidic chips can achieve a variety of functions, such as fluid manipulation, sample processing, biochemical reactions, etc. These functions make microfluidic chips have very broad application prospects, especially its application in the fields of biology and medicine is of great significance.

[0003] At present, the main method for whole blood separation in clinical practice is through plasma separation. There are two types of plasma separation: centrifugation and membrane separation. According to the degree of fine separation of pathogenic substances in plasma, it can be divided into selective and non-selective. (1) Centrifugal plasma separation method: After the 1960s, closed plasma separation devices were used. The plasma separator was used to introduce blood into a bell-shaped centrifuge cup. The centrifugal effect was used to keep the light plasma above the cup and the heavy cell components below the cup, thereby separating the plasma. This method not only separates plasma, but also can adjust different centrifugal speeds according to the differences in the specific gravity of various components in the blood to separate different blood components. (2) Membrane plasma separation: In 1978, membrane plasma separators began to be used in clinical practice. Modern membrane plasma separators are made of polymer material membranes with high permeability and good biocompatibility. Blood passes through a hollow fiber filter, and filters with different membrane pore sizes can separate substances of different molecular weights. Therefore, membrane separation can be used for both non-selective and selective plasma separation. However, it is difficult to achieve quantitative separation using this membrane separation method, and the measurement results are unstable. In addition, this technology requires the use of centrifugal equipment, which is relatively expensive.

[0004] In summary, there is an urgent need in the art to develop a new blood filtration chip that can quantitatively separate plasma and does not require the use of a centrifugal device. Summary of the invention

[0005] The purpose of the present invention is to provide a new blood filter chip which can quantitatively separate plasma and does not need to be used with a centrifugal device.

[0006] In a first aspect of the present invention, a quantitative blood filtration chip is provided, the chip comprising a chip body (1);

[0007] in,

[0008] The chip body comprises: a blood filtering mechanism (2), a liquid storage mechanism (3) in fluid communication with the blood filtering mechanism, and an indication mechanism (5) in fluid communication with the liquid storage mechanism;

[0009] The blood filtering mechanism is used to filter whole blood;

[0010] The liquid storage mechanism comprises: a liquid storage tank (32) and a liquid storage outlet (31) located at the bottom surface of the liquid storage tank (32); wherein the volume of the liquid storage tank is V 储 The top of the liquid storage tank has a top opening, and the outlet area S of the liquid storage outlet is small enough so that the liquid in the liquid storage tank will not flow out without external force; and

[0011] At least a portion of the indicator structure is transparent and the indicator structure is used to indicate whether the filtered blood in the reservoir of the reservoir mechanism has filled the reservoir.

[0012] In another preferred embodiment, the filtered blood is plasma.

[0013] In another preferred embodiment, the chip body further comprises a first microchannel (6) for connecting the blood filtering mechanism and the liquid storage mechanism.

[0014] In another preferred embodiment, the outlet area S of the liquid storage outlet (31) is ≤ 3.2 mm 2 ; Preferably, 0.8mm 2 ≤S≤3.2mm 2 .

[0015] In another preferred embodiment, the liquid storage outlet is a circular outlet (ie, the cross-section of the liquid storage outlet is circular).

[0016] In another preferred embodiment, the outlet diameter D of the liquid storage outlet is ≤2 mm; preferably, 1 mm ≤ D ≤ 2 mm.

[0017] In another preferred embodiment, the volume V of the liquid storage tank is 储 28μL~42μL.

[0018] In another preferred embodiment, 8mm≤V 储 / S≤53mm.

[0019] In another preferred embodiment, the height H of the liquid storage tank is 储 1 to 10 mm; preferably, H 储 =1-8mm; preferably, H 储 =2~6mm; optimally, H 储 =4±1mm.

[0020] In another preferred embodiment, the bottom surface of the liquid storage tank is circular.

[0021] In another preferred embodiment, the liquid storage tank is a columnar (preferably cylindrical) or inverted cone-shaped (i.e., a cone-shaped structure with an upper bottom surface larger than a lower bottom surface (i.e., the bottom surface of the liquid storage tank), preferably, an inverted truncated cone-shaped) liquid storage tank.

[0022] In another preferred embodiment, D 储 >D; preferably, D 储 ≥1.5D; preferably, 1.5D≤D 储 ≤2.5D.

[0023] In another preferred embodiment, when the volume of the liquid storage tank V 储 =28μL~34μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.1~0.8; preferably, D 储 / H 储 =0.6-0.8; more preferably, D 储 / H 储 =0.75 ±0.05; optimally, D 储 / H 储 =0.75±0.02.

[0024] In another preferred embodiment, when the volume of the liquid storage tank V 储 =36 μL to 42 μL (preferably, 38 to 42 μL), the ratio of the diameter of the bottom surface of the reservoir to the height of the reservoir D 储 / H 储 =0.8~1.0; preferably, D 储 / H 储 =0.9±0.05; more preferably, D 储 / H 储 =0.9±0.03.

[0025] In another preferred embodiment, when the released volume V of the filtered blood is 释放 =17-19 μL (preferably, 17.5-18.5 μL), the ratio of the diameter of the bottom surface of the reservoir to the height of the reservoir is D 储 / H 储 =0.1~0.8; preferably, D 储 / H 储 =0.6-0.8; more preferably, D 储 / H 储 =0.75±0.05; optimally, D 储 / H 储 =0.75±0.02.

[0026] In another preferred embodiment, when the released volume V of the filtered blood is 释放 =20-22 μL (preferably, 20-21 μL), the ratio of the diameter of the bottom surface of the reservoir to the height of the reservoir is D 储 / H 储 =0.8~1.0; preferably, D储 / H 储 =0.9±0.05; more preferably, D 储 / H 储 =0.9±0.03.

[0027] In another preferred embodiment, when the minimum sample volume V 样品 =17-19 μL (preferably, 17.5-18.5 μL), the ratio of the diameter of the bottom surface of the reservoir to the height of the reservoir is D 储 / H 储 =0.1~0.8; preferably, D 储 / H 储 =0.6-0.8; more preferably, D 储 / H 储 =0.75±0.05; optimally, D 储 / H 储 =0.75±0.02.

[0028] In another preferred embodiment, when the minimum sample volume V 样品 =20-22 μL (preferably, 20-21 μL), the ratio of the diameter of the bottom surface of the reservoir to the height of the reservoir D 储 / H 储 =0.8~1.0; preferably, D 储 / H 储 =0.9±0.05; more preferably, D 储 / H 储 =0.9±0.03.

[0029] In another preferred embodiment, the diameter D of the bottom surface of the liquid storage tank is 储 Greater than 2 to 10 mm; preferably, D 储 =3-10 mm; more preferably, D 储 =3~5mm; optimally, D 储 =3.4~5mm.

[0030] In another preferred embodiment, when H 储 =4±2mm (preferably, H 储 =4±1mm; preferably 4±0.5mm), the diameter D of the bottom surface of the liquid reservoir 储 2 to 8 mm; preferably, D 储 =2-4 mm; preferably, D 储 =2.8~3.8mm; optimally, D 储 =3.0±0.1mm or 3.6±0.1mm.

[0031] In another preferred embodiment, when the volume of the liquid storage tank V 储=28μL~34μL, the diameter D of the bottom of the reservoir 储 =3±0.2mm; preferably, D 储 =3±0.1mm.

[0032] In another preferred embodiment, when the volume of the liquid storage tank V 储 =36 μL to 42 μL (preferably, 38 to 42 μL), the diameter D of the bottom surface of the reservoir 储 =3.6±0.2mm; preferably, D 储 =3.6±0.1mm.

[0033] In another preferred embodiment, when the released volume V of the filtered blood is 释放 =17-19 μL (preferably, 17.5-18.5 μL), the diameter D of the bottom surface of the reservoir 储 =3±0.2mm; preferably, D 储 =3±0.1 mm.

[0034] In another preferred embodiment, when the released volume V of the filtered blood is 释放 =20-22 μL (preferably, 20-21 μL), the diameter D of the bottom surface of the reservoir 储 =3.6±0.2mm; preferably, D 储 =3.6±0.1mm.

[0035] In another preferred embodiment, when the minimum sample volume V 样品 =50±5μL (preferably, 50±3μL; more preferably, 50±1μL), the diameter D of the bottom surface of the reservoir 储 =3±0.2mm; preferably, D 储 =3±0.1mm.

[0036] In another preferred embodiment, when the minimum sample volume V 样品 =60±5μL (preferably, 60±3μL; more preferably, 60±1μL), the diameter D of the bottom surface of the reservoir 储 =3.6±0.2mm; preferably, D 储 =3.6± 0.1mm.

[0037] In another preferred example, the inner wall of the liquid storage tank is perpendicular to the bottom surface.

[0038] In another preferred embodiment, the bottom area S of the liquid storage tank is 储 ≥S.

[0039] In another preferred embodiment, the area of ​​the top opening of the liquid storage tank is ≥ the average cross-sectional area of ​​the liquid storage tank.

[0040] In another preferred embodiment, the area of ​​the top opening of the liquid storage tank is ≥ the maximum cross-sectional area of ​​the liquid storage tank.

[0041] In another preferred embodiment, the bottom surface of the liquid storage tank is a bottom surface that has been subjected to hydrophilic modification.

[0042] In another preferred embodiment, the liquid storage outlet is a liquid storage outlet that has been hydrophilically modified.

[0043] In another preferred embodiment, the blood filtering mechanism comprises:

[0044] a blood inlet (21), wherein the blood inlet is used to add blood to be filtered;

[0045] A blood filter membrane cavity (22), wherein the blood filter membrane cavity is used to accommodate the blood filter membrane;

[0046] a collecting chamber (27), the collecting chamber being used to collect filtered blood, and the collecting chamber further comprising a supporting structure (24) for supporting the blood filtering membrane (23); and

[0047] A blood filtration outlet (26) is fluidically connected to the liquid storage mechanism (preferably, the filtered blood in the collection chamber flows into the liquid storage tank via the blood filtration outlet and the first microchannel).

[0048] In another preferred example, the height of the collecting chamber is 1 mm to 2 mm.

[0049] In another preferred embodiment, the support structure (24) has a support surface, and the support surface is used to support the blood filter membrane (23).

[0050] In another preferred embodiment, the support structure (24) is a support column distributed in the collection chamber.

[0051] In another preferred embodiment, the support structure (24) is a support plate having a plurality of through holes (25).

[0052] In another preferred embodiment, the bottom surface of the collection chamber is a hydrophilic bottom surface.

[0053] In another preferred embodiment, the hydrophilic bottom surface of the collection chamber is a hydrophilic bottom surface formed by directly or indirectly adhering one or more hydrophilic films to the bottom surface of the collection chamber, or a hydrophilic bottom surface formed by hydrophilically modifying the bottom surface of the collection chamber, or a hydrophilic bottom surface prepared with a hydrophilic material.

[0054] In another preferred embodiment, the blood inlet is arranged at the top of the blood filter membrane cavity; preferably, it is arranged at the center of the blood filter membrane cavity.

[0055] In another preferred embodiment, the blood filtration outlet is disposed at the bottom of the collection chamber; preferably, it is disposed at the bottom center of the collection chamber.

[0056] In another preferred embodiment, the blood filter membrane cavity matches the blood filter membrane.

[0057] In another preferred embodiment, the collection chamber matches the shape of the blood filter membrane.

[0058] In another preferred embodiment, the blood filtering mechanism further includes a blood filtering membrane (23) pre-placed therein.

[0059] In another preferred embodiment, in the blood filtering mechanism, from top to bottom, there are: a blood inlet (21), a blood filtering membrane cavity (22), an optional blood filtering membrane (23), a collection chamber (27) and a blood filtering outlet (26).

[0060] In another preferred embodiment, the indicator mechanism includes an indicator groove (52) and a second microchannel (51), and at least a portion of the indicator groove and / or the second microchannel is transparent (when the reservoir is full of filtered blood, the filtered blood will enter the second microchannel, so that the experimenter can observe the microchannel filled with blood through the transparent side around the second microchannel).

[0061] In another preferred embodiment, the total volume of the indicating mechanism (preferably, the indicating groove and the second microchannel) is 0.1 to 1 times the volume of the liquid storage tank.

[0062] In another preferred example, the indicating mechanism is only in fluid communication with the liquid reservoir.

[0063] In another preferred embodiment, the indicating mechanism (preferably, the second microchannel) is connected to the top of the liquid storage tank.

[0064] In another preferred embodiment, the material of the chip body is a biocompatible polymer material.

[0065] In another preferred embodiment, the material of the chip body is selected from the following group: polymer polydimethylsiloxane (PDMS), thermoplastic material polymethyl methacrylate (PMMA), polycarbonate (PC), polystyrene (PS), or a combination thereof.

[0066] In another preferred embodiment, the inner diameter (or equivalent inner diameter) of the first microchannel is 1 mm to 2 mm.

[0067] In another preferred embodiment, the cross-section of the first microchannel is rectangular.

[0068] In another preferred embodiment, the inner diameter (or equivalent inner diameter) of the second microchannel is 1 mm to 2 mm.

[0069] In another preferred embodiment, the cross-section of the second microchannel is rectangular.

[0070] In another preferred embodiment, the appearance shape of the first microchannel and / or the second microchannel is selected from the following group: a straight channel, a curved channel, an arc-shaped channel, or a combination thereof.

[0071] In another preferred embodiment, the chip further comprises: a pressurizing mechanism (4); the pressurizing mechanism is used to apply external force to the liquid reservoir, so that the filtered blood in the liquid reservoir flows out of the chip body through the liquid reservoir outlet.

[0072] In another preferred example, the pressurizing mechanism includes: a syringe pump and a syringe.

[0073] In another preferred embodiment, the pressurizing mechanism has a connector, and the connector is provided with a pressurizing outlet with a cross-sectional area larger than the opening of the liquid reservoir, so that pressure can be evenly applied to the filtered blood in the liquid reservoir.

[0074] In another preferred embodiment, the pressurizing mechanism can also provide negative pressure (for accelerating the filtration speed and / or controlling the filtration time).

[0075] In another preferred example, the chip body further comprises a first limiting structure (71), and the first limiting structure is used to limit the position of the pressurizing mechanism.

[0076] In another preferred example, the chip body further includes a second limiting structure (72).

[0077] In another preferred example, the limiting mechanism is a groove, and the groove matches the connector.

[0078] The second aspect of the present invention provides a use of the quantitative blood filtration chip as described in the first aspect, for filtering whole blood and quantitatively obtaining plasma.

[0079] The third aspect of the present invention provides a kit, which comprises the quantitative blood filtration chip as described in the first aspect.

[0080] In another preferred embodiment, the kit further includes a blood injection mechanism.

[0081] In another preferred embodiment, the kit further comprises a label or instructions, wherein the label or instructions indicate that the kit is used for whole blood filtration and plasma quantification.

[0082] In another preferred embodiment, the kit further comprises a reagent strip for detecting a plasma sample.

[0083] It should be understood that within the scope of the present invention, the above-mentioned technical features of the present invention and the technical features specifically described below (such as embodiments) can be combined with each other to form a new or preferred technical solution. Due to space limitations, they will not be described one by one here. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] Figure 1 The overall structural schematic diagram of the blood filtration chip of the present invention is shown;

[0085] Figure 2 A schematic diagram of the blood filtration mechanism in the blood filtration chip of the present invention is shown;

[0086] Figure 3 A side schematic diagram of the blood filtration chip of the present invention is shown;

[0087] Figure 4 It is a schematic cross-sectional view of a chip body in a specific embodiment of the present invention.

[0088] Figure 5A and 5B For Figure 4 The schematic top view of the chip body in the specific embodiment shown, wherein 5A is a schematic top view of the top cover layer and the blood filter membrane upper cover layer (AA surface) and 5B is a schematic top view of the main chip excluding the top cover layer and the blood filter membrane cover layer (BB surface).

[0089] Figure 6 Hemolysis at different filtration times is shown.

[0090] Figure 7 A schematic diagram of a reservoir structure having an inverted truncated cone shape is shown.

[0091] Figure 8 A schematic diagram showing the combination of the blood filtration chip of the present invention and other chips is shown.

[0092] The symbols in the figure are as follows:

[0093] 1 is the chip body, 2 is the blood filtering mechanism (blood filtering port), 3 is the liquid storage mechanism, 4 is the pressurizing mechanism, 5 is the indicating mechanism, and 6 is the first microchannel;

[0094] 11 is the top cover layer, 12 is the upper cover layer of the blood filter membrane, 131 is the collection chamber layer, 132 is the hydrophilic membrane constituting the bottom surface of the collection chamber, 14 is the bottom plate of the blood filter port and the indicator layer, 15 is the interlayer, 16 is the blood filter outlet layer, and 17 is the main body bottom plate layer; 21 is the blood inlet, 22 is the blood filter membrane cavity, 23 is the blood filter membrane, 24 is the support structure, 25 is the perforation on the support plate, 26 is the blood filter outlet, and 27 is the main body chamber;

[0095] 31 is the liquid storage outlet, 32 is the liquid storage tank; 51 is the second microchannel, 52 is the indicator tank;

[0096] 71 is a first limiting mechanism, 72 is a second limiting mechanism;

[0097] 8 is a lateral flow chromatography test piece, 81 is a sample pad of the test piece, 82 is an NC membrane, 83 is an absorption pad, and 84 is a sample injection port of a reagent strip.

[0098] the term

[0099] As used herein, the terms "comprise", "include", and "contain" are used interchangeably and include not only closed definitions, but also semi-closed and open definitions. In other words, the terms include "consisting of", "consisting essentially of".

[0100] Unless otherwise specified, in this document, the term "diameter" may also refer to an equivalent diameter. The "equivalent diameter" refers to the diameter of a circle with the same area as a certain shape when the shape is non-circular.

[0101] As used herein, S refers to the outlet area of ​​the reservoir outlet, which represents the cross-sectional area of ​​the reservoir outlet or the reservoir outlet size, and D refers to the diameter (or equivalent diameter) of the outlet of the reservoir outlet;

[0102] V 储 refers to the volume of the reservoir, H 储 Refers to the height of the reservoir, D 储 Refers to the bottom diameter (or equivalent diameter) of the reservoir, S 储 Refers to the bottom area of ​​the liquid reservoir;

[0103] V 释放 It refers to the released volume of filtered blood of the quantitative blood filtration chip of the present invention, that is, the volume of filtered blood that can be obtained by the quantitative blood filtration chip of the present invention;

[0104] V 样品 It refers to the minimum sample loading volume of the quantitative blood filtration chip of the present invention, that is, the sample loading volume that can fill the liquid storage tank of the blood filtration chip of a specific embodiment. DETAILED DESCRIPTION

[0105] After extensive and in-depth research, the inventors have designed for the first time a quantitative blood filtration chip with a simple structure and easy processing. The volume of filtered blood obtained by using the blood filtration chip of the present invention for blood filtration is stable and has little impact on the test results, and the test results are accurate. In addition, the inventors unexpectedly found that by controlling the proportional relationship between the bottom surface area of ​​the liquid storage tank and its height, the coefficient of variation (CV) of the volume of the obtained liquid such as filtered blood can be further reduced. Based on this, the inventors have completed the present invention.

[0106] Quantitative blood filtration chip

[0107] In order to solve the problem in the prior art that it is difficult to quantitatively separate plasma by membrane separation, the present invention provides a quantitative blood filtration chip including a chip body having a blood filtration mechanism and a liquid storage tank.

[0108] In one embodiment, a quantitative blood filtration chip is provided, which includes a chip body, and the chip body is provided with a blood filtration port (i.e., a blood filtration mechanism), a liquid storage tank, and an indication mechanism, and the blood filtration port and the liquid storage tank are fluidically connected, and the liquid storage tank and the indication mechanism are fluidically connected.

[0109] In a preferred example, the liquid storage tank and the blood filtration port are connected via a microchannel (ie, the first microchannel).

[0110] In the present application, the bottom of the liquid reservoir is provided with an opening (i.e., a liquid reservoir outlet), and the diameter or cross-sectional area of ​​the opening is small enough so that the plasma in the liquid reservoir will not flow out autonomously without external force; preferably, the diameter of the opening is less than or equal to 2 mm (preferably, 1 to 2 mm). Preferably, the surface of the bottom of the liquid reservoir is a hydrophilic surface.

[0111] In the present application, the amount of plasma obtained can be fixed by the size of the reservoir (volume), thereby achieving the purpose of quantitative blood filtration, that is, the volume of the reservoir determines the amount of plasma quantitatively removed; therefore, the present application does not specifically limit the size (such as volume, etc.) of the reservoir, and the size of the reservoir can be adjusted according to the needs of actual application. Preferably, the reservoir is approximately columnar or truncated (such as Figure 7 The liquid reservoir is preferably a cylindrical liquid reservoir. Preferably, the diameter D of the bottom surface of the liquid reservoir is 储 Greater than 2 to 10 mm; preferably, D 储 =3-10 mm; more preferably, D 储 =3~5mm; optimally, D 储 =3.4~5mm.

[0112] In a preferred embodiment, at a certain reservoir volume (or average release volume or sample volume), the present application prefers a lower reservoir bottom area (for example, while maintaining a lower reservoir bottom area, increasing the height of the reservoir to achieve a target reservoir volume).

[0113] In one embodiment, when the volume of the reservoir V 储 =28 μL to 34 μL and / or when the released volume of filtered blood is V 释放 =17-19 μL (preferably, 17.5-18.5 μL) and / or when the minimum sample volume V 样品 =50±5μL (preferably, 50±3μL; more preferably, 50±1μL), D 储 / H 储 (i.e., the ratio of the diameter of the bottom surface of the liquid reservoir to the height of the liquid reservoir) = 0.1 to 0.8; preferably, D 储 / H 储 =0.6-0.8; more preferably, D 储 / H 储 =0.75±0.05; optimally, D 储 / H 储 =0.75±0.02.

[0114] In another specific embodiment, when the reservoir volume V 储 =36 μL to 42 μL (preferably, 38 to 42 μL) and / or when the released volume of the filtered blood is V 释放 =20-22 μL (preferably, 20-21 μL) and / or the diameter D of the bottom surface of the reservoir 储 =3±0.2mm; preferably, D 储 =3±0.1mm.

[0115] In one embodiment, when the volume of the reservoir V 储 =36 μL to 42 μL (preferably, 38 to 42 μL) and / or when the released volume of the filtered blood is V 释放 =20-22 μL (preferably, 20-21 μL) and / or when the minimum sample volume V 样品 =60±5μL (preferably, 60±3μL; more preferably, 60±1μL), D 储 / H 储 =0.8~1.0; preferably, D 储 / H 储 =0.9±0.05; more preferably, D 储 / H 储 =0.9±0.03.

[0116] In another specific embodiment, when the reservoir volume V 储 =36 μL to 42 μL (preferably, 38 to 42 μL) and / or when the released volume of the filtered blood is V 释放 =20-22 μL (preferably, 20-21 μL) and / or when the minimum sample volume V 样品 =60±5μL (preferably, 60±3μL; more preferably, 60±1μL), the diameter D of the bottom surface of the reservoir 储 =3.6±0.2mm; preferably, D 储 =3.6±0.1mm.

[0117] In a specific embodiment, the bottom of the liquid reservoir is connected to a microchannel (i.e., a first microchannel) for allowing the plasma in the blood filter port to flow into the liquid reservoir. Preferably, the bottom surface of the liquid reservoir is a hydrophilic bottom surface, which is used to help the plasma to be discharged from the liquid reservoir (or to help the plasma enter a storage container such as a centrifuge tube or a subsequent chip) to reduce the quantitative error caused by the plasma sticking to the wall.

[0118] In the present application, the hydrophilic surface (such as the bottom surface, etc.) can be made of a hydrophilic material (such as PET, PC, ABS, etc.), or the surface can be obtained by hydrophilic modification. The "hydrophilic modification" can be carried out by various methods disclosed in the art, such as adding a hydrophilic membrane between the structures (for example, adding a hydrophilic membrane between the layer with the collection chamber structure and the layer with the blood filtration outlet structure), hydrophilic modification of the surface to be treated (for example, plasma treatment, NaOH immersion, grafting modification, nano-coating modification, or a combination thereof), etc.

[0119] In this application, see Figure 2 , the blood filtering mechanism (blood filtering port) generally includes: an inlet (blood inlet), an optional blood filtering membrane, a collection chamber and an outlet (blood filtering outlet); the blood filtering port is used to separate blood cells and plasma. In a specific embodiment, the collection chamber includes: a main chamber 27 and a support structure 24 for supporting the blood filtering membrane provided in the main chamber (such as a support plate provided on the upper part of the main chamber, and one or more perforations 25 are provided on the support plate), and the support structure has a support surface, and the blood filtering membrane is provided on the support surface. Preferably, the inlet is above the blood filtering membrane. Preferably, the bottom surface of the collection chamber is a hydrophilic bottom surface, which is used to help the filtered blood enter subsequent structures such as a liquid storage tank. In the present application, there is no special requirement for the blood filtering membrane, and commercially available blood filtering membranes can be used, for example, Pall, Vivid Plasma Separatien.

[0120] In the present application, an indicator mechanism is connected to the top of the reservoir, which is used to store the plasma overflowing from the reservoir and indicate that the reservoir is full of plasma. In a specific embodiment, the top (top) of the reservoir is connected to an indicator slot through a microchannel (i.e., the second microchannel). After the plasma storage amount in the reservoir reaches a specified amount, the plasma will flow to the indicator slot through the microchannel. There is no special limitation on the shape of the indicator slot in the present application, as long as it is sufficient to accommodate the excess filtered blood overflowing the reservoir and enable the experimenter to observe the blood in the indicator slot. Preferably, the total volume of the indicator mechanism (such as the total volume of the indicator slot and the second microchannel) is 0.1 to 1 times the volume of the reservoir, so that the indicator mechanism can not only be used to indicate that the blood filter slot is full, but also can accommodate the excess filtered blood overflowing the reservoir; thereby avoiding the blood in the indicator mechanism from flowing back into the reservoir when the filtered blood is discharged.

[0121] In the present application, the chip body is generally made of a biocompatible polymer material. Preferably, the biocompatible polymer material is selected from: polymer polydimethylsiloxane PDMS, thermoplastic material polymethyl methacrylate PMMA, polycarbonate PC, polystyrene PS, or a combination thereof.

[0122] In one embodiment, the chip body of the present application includes multiple layers of biocompatible polymer materials with corresponding structures, and the layers can be fixed using double-sided tape or other conventional techniques in the art (for example, used for other microfluidic chip fixing methods) to assemble the chip body.

[0123] In a specific embodiment, Figure 4 , 5A As shown in Figure 5B, the chip body is composed of an optional top cover layer 11, a blood filter membrane upper cover layer 12, a support layer, a blood filter port bottom plate and an indicator layer 14, an interlayer 15, a blood filter outlet layer 16 and a main body bottom plate layer 17; wherein each layer is processed into a specific structural unit or a whole, and each layer is assembled to form the blood filter mechanism 2, the liquid storage mechanism 3 and the indicator mechanism 5 of the main chip.

[0124] In another specific embodiment, the chip body includes the following layers:

[0125] (a) The top cover layer 11 is provided with a partial structure of the first limiting structure 71, a partial structure of the second limiting structure 72 and a partial structure of the indicator groove 52;

[0126] (b) The upper cover layer 12 of the blood filter membrane is provided with a blood inlet 21, a blood filter membrane cavity 22, a partial structure of the first limiting structure 71 and a partial structure of the indicator groove 52;

[0127] (c) The support layer is provided with a collection chamber, a part of the first limiting structure 71 and a part of the indicating groove 52, and the support layer is composed of a collection chamber layer 131 and a hydrophilic membrane 132 as the bottom surface of the collection chamber;

[0128] The collection chamber layer includes a main chamber 27 and a support structure 24 provided in the main chamber. The support structure is a support plate 23 for supporting the blood filter membrane, and the support plate is provided with a plurality of perforations 25. Preferably, a gap for allowing the filtered blood to flow into the blood filter outlet is reserved between the support plate and the hydrophilic membrane as the bottom surface of the collection chamber 132; the hydrophilic membrane has an opening corresponding to the blood filter outlet 26;

[0129] (d) The blood filter port bottom plate and the indicator layer 14 are provided with a partial structure of the blood filter port 26, a second microchannel 51, a partial structure of the indicator tank 52 and a partial structure of the liquid reservoir 3;

[0130] (e) the interlayer 15 is provided with a partial structure of the blood filtration outlet 26 and a partial structure of the liquid storage tank 32;

[0131] (f) the blood filtration outlet layer 16 is provided with a partial structure of the blood filtration outlet 26, a partial structure of the first microchannel 6 and a liquid reservoir 32; and

[0132] (g) The main body bottom plate layer 17 is made of a hydrophilic material (such as a hydrophilic film) to form a hydrophilic bottom surface of the liquid storage tank, and the main body bottom plate layer is provided with an opening serving as a liquid storage outlet 31 (for example, the opening diameter ≤ 2 mm, such as a diameter of 1.6 mm).

[0133] Although in the above-mentioned specific embodiments, the chip body of the blood filtration chip of the present invention is formed by processing corresponding structures in each layer and assembling them, it should be understood that as long as the blood filtration mechanism, liquid storage mechanism, indication mechanism, etc. described in the present application are processed by any method (such as injection molding, 3D printing, and selecting materials and / or treating the surface according to the needs of each structure), the purpose of the present application can be achieved.

[0134] In another embodiment, the quantitative blood filtration chip further comprises a pressurizing mechanism, which is used to apply external force to the filtered blood in the reservoir, thereby expelling the quantitatively separated plasma in the reservoir. Preferably, the pressurizing mechanism is a syringe. In another preferred example, the pressurizing mechanism (such as a syringe) is used to push out the plasma in the reservoir, and the diameter of the pressurizing outlet of the pressurizing mechanism is larger than the diameter of the reservoir. In another preferred example, the pressurizing mechanism (such as a syringe) has a connector provided with a pressurizing outlet. In the present application, the syringe can be made of thermoplastic material polymethyl methacrylate PMMA, or polycarbonate PC, or polystyrene PS or metal material. Preferably, the syringe comprises a syringe barrel, a plunger rod, a connecting column and a nut.

[0135] In addition to being able to be used independently for blood filtration, the chip of the present invention can also be used in combination with other chips or other functional modules. Figure 8 As shown, the outlet of the liquid reservoir of the quantitative blood filtration chip of the present invention can be directly or indirectly connected to the sample pad of the lateral flow chromatography reagent sheet (8) (e.g., through the sample port (84), such as the sample port on the shell of the reagent strip), and the whole blood (e.g., plasma) after quantitative filtration is transported to the test area on the NC membrane (82) through the capillary action of the sample pad (81) and the absorption pad (83) for detection. Alternatively, the chip of the present invention can also be combined with a microfluidic chip, and the liquid can be controlled to flow into the test area by a syringe pump, so as to perform subsequent detection of the plasma.

[0136] Preparation method of blood filtration chip

[0137] The blood filtration chip of the present invention can be prepared by various processing methods known in the art, such as various known methods for preparing microfluidic chips (e.g., mechanical cutting assembly, 3D printing, injection molding, photolithography assembly, soft etching, and microcontact printing, etc.) to obtain the chip of the present invention.

[0138] How to use the blood filter chip

[0139] The present invention also provides a method for quantitative blood filtration, the method comprising the steps of:

[0140] (1) Providing a quantitative blood filtration chip as described in the first aspect;

[0141] (2) injecting the blood to be filtered into the blood inlet of the blood filter port of the chip for filtering; and

[0142] (3) applying external force to the filtered blood in the reservoir to obtain filtered blood (preferably, obtaining filtered blood quantitatively).

[0143] Preferably, 100 μL to 300 μL of blood (whole blood) is injected.

[0144] Preferably, the blood filtration time is 2.5 to 3.5 minutes.

[0145] Preferably, in step (2), blood (whole blood) is added to the blood inlet via a syringe, a pipette, a dropper, etc.

[0146] The main advantages of the present invention include:

[0147] (a) Simple structure and low processing difficulty.

[0148] (b) Capable of quantitatively separating blood.

[0149] (c) The chip of the present invention has little impact on subsequent detection and has a small detection error.

[0150] (d) It is easy to use and does not require any equipment such as a centrifuge.

[0151] (e) Blood (about 100 μL to 300 μL) is directly added to the chip. Filtration usually takes only 3-5 minutes (depending on the amount of filtered blood).

[0152] (f) It can be used in conjunction with other detection chips or reagent strips, which is convenient and fast.

[0153] The present invention will be further described below in conjunction with specific examples and accompanying drawings. It should be understood that these examples and accompanying drawings are only used to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods for the unrecorded specific conditions in the following examples are usually based on conventional conditions or the conditions recommended by the manufacturer. Unless otherwise stated, percentages and parts are weight percentages and weight parts.

[0154] Example 1.1

[0155] (1) The diameter of the blood filter membrane is set to 2 cm, the diameter of the liquid reservoir is 3 mm-3.6 mm, and the height of the liquid reservoir is 4 mm. After each layer of the chip is mechanically cut out, it is fixed with double-sided tape, and a hydrophilic membrane is added between the support layer and the bottom plate of the blood filter membrane. The structure is as follows Figure 4 , 5A and 5B.

[0156] (2) After quantitatively measuring the liquid with a pipette, inject it into the blood filter port and measure the release volume of the liquid reservoir. The results are shown in Table 1.

[0157] Table 1: Reservoir release volume determination

[0158] Reservoir diameter d(mm) Sample volume / average release volume (μL) Coefficient of variation CV 3.6 60 / 20.7 5.41％ 3.2 50 / 18.0 9.61％ 3.0 50 / 18.2 6.36％

[0159] Note: When the reservoir diameter is 3.6 mm and the sample volume is 50 μL, the filtered liquid cannot fill the reservoir.

[0160] During the test, the residual volume at the reservoir and the bottom plate outlet is not fixed and the residual volume of structures of different sizes is different, resulting in different CVs of the released volume. The experimental results show that when the reservoir diameter is 3.6mm, the CV (coefficient of variation) of the released volume is small.

[0161] Example 1.2

[0162] (1) The diameter of the blood filter membrane is set to 2 cm, and the diameter of the liquid reservoir is set to 3.6 mm. After each layer of the chip is mechanically cut out, it is fixed with double-sided tape, and a hydrophilic membrane is added between the support layer and the bottom plate of the blood filter membrane.

[0163] (2) 200 μL of whole blood was injected at the inlet, and the whole blood was flowed through the blood filter membrane in a timed and quantitative manner using a syringe pump. The time was controlled to be different from 2 min to 10 min (i.e., different injection speeds). The results are shown in Figure 5.

[0164] The results showed that when the whole blood injection volume was 200 μL, the blood filtration time was controlled at 3 minutes, and the effect was optimal. If the time was too long, hemolysis would occur. Figure 6 shown.

[0165] Example 2

[0166] The steps were the same as in Example 1.2, except that the whole blood was replaced with BNP calibrators of different concentrations (400 pg / mL and 1600 pg / mL), and the results were subjected to lateral flow chromatography fluorescence immunoassay after passing through the filter membrane, and compared with the unfiltered standard. The results are shown in Table 2.

[0167] Table 2

[0168]

[0169] In the table, TA and CA are the fluorescence signal values ​​of the T line and C line of the lateral flow chromatography test piece, respectively, TAP=TA / (TA+CA)*5000, and the TAP value is related to the concentration of the calibrator.

[0170] It can be seen from the data results that the quantitative blood filtration device of the present invention has limited adsorption of proteins and has little overall impact on the test results.

[0171] in conclusion

[0172] It can be seen from the examples that the quantitative blood filtration device designed by the present invention can complete blood filtration in a timely and quantitative manner, and the deviation caused by protein adsorption is within a controllable range.

[0173] All documents mentioned in the present invention are cited as references in this application, just as each document is cited as reference individually. In addition, it should be understood that after reading the above teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. A quantitative blood filtration chip, characterized in that: The chip comprises a chip body (1); in, The chip body comprises: a blood filtering mechanism (2), a liquid storage mechanism (3) in fluid communication with the blood filtering mechanism, and an indication mechanism (5) in fluid communication with the liquid storage mechanism; The blood filtering mechanism is used to filter whole blood; The liquid storage mechanism comprises: a liquid storage tank (32) and a liquid storage outlet (31) located at the bottom surface of the liquid storage tank (32); wherein the volume of the liquid storage tank is V 储 The top of the liquid storage tank has a top opening, and the cross-sectional area S of the liquid storage outlet is small enough so that the liquid in the liquid storage tank will not flow out without external force; and the bottom surface area S of the liquid storage tank is 储 ≥S, and the area of ​​the top opening of the liquid reservoir is ≥ the maximum cross-sectional area of ​​the liquid reservoir; and At least a portion of the indicator mechanism is transparent and the indicator mechanism is used to indicate whether the filtered blood in the reservoir of the reservoir mechanism has filled the reservoir.

2. The quantitative blood filtration chip according to claim 1, characterized in that: The outlet area S of the liquid storage outlet (31) is ≤ 3.2 mm 2 .

3. The quantitative blood filtration chip according to claim 1, characterized in that: The outlet area of ​​the liquid storage outlet (31) is 0.8 mm 2 ≤S≤3.2mm 2 .

4. The quantitative blood filtration chip according to claim 1, characterized in that: The outlet diameter D of the liquid storage outlet is ≤ 2 mm.

5. The quantitative blood filtration chip according to claim 1, characterized in that: The outlet diameter of the liquid storage outlet is 1mm≤D≤2mm.

6. The quantitative blood filtration chip according to claim 1, characterized in that: The volume V of the liquid storage tank 储 28μL~42μL.

7. The quantitative blood filtration chip according to claim 1, characterized in that: D 储 >D。 8. The quantitative blood filtration chip according to claim 1, characterized in that: <h2 style=";text-align:left;direction:ltr">D<h2 style=";text-align:left;direction:ltr"> 储 <h2 style=";text-align:left;direction:ltr"> ≥1.5D.

9. The quantitative blood filtration chip according to claim 1, characterized in that: 1.5D≤D 储 ≤2.5D.

10. The quantitative blood filtration chip according to claim 1, characterized in that: The liquid reservoir has one or more of the following characteristics: (a) When the volume of the reservoir is V 储 =28μL~34μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.1~0.8; (b) When the volume of the reservoir is V 储 =36μL~42μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.8~1.0; (c) When the released volume of filtered blood V 释放 =17~19μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.1~0.8; (d) When the released volume of filtered blood V 释放 =20~22μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.8~1.0; (e) When the minimum sample volume V 样品 =17~19μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.1-0.8; and / or (f) When the minimum sample volume V 样品 =20~22μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.8~1.

0.

11. The quantitative blood filtration chip according to claim 1, characterized in that: The liquid reservoir has one or more of the following features: (a) When the volume of the reservoir is V 储 =28μL~34μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.6~0.8; (b) When the volume of the reservoir is V 储 =36μL~42μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.9±0.05; (c) When the released volume of filtered blood V 释放 =17~19μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.6~0.8; (d) When the released volume of filtered blood V 释放 =20~22μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.9±0.05; (e) When the minimum sample volume V 样品 =17~19μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.6~0.8; and / or (f) When the minimum sample volume V 样品 =20~22μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.9±0.

05.

12. The quantitative blood filtration chip according to claim 1, characterized in that: The liquid reservoir has one or more of the following features: (a) When the volume of the reservoir is V 储 =28μL~34μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.75±0.05; (b) When the volume of the reservoir is V 储 =36μL~42μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.9±0.03; (c) When the released volume of filtered blood V 释放 =17~19μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.75±0.05; (d) When the released volume of filtered blood V 释放 =20~22μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.9±0.03; (e) When the minimum sample volume V 样品 =17~19μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.75±0.05; and / or (f) When the minimum sample volume V 样品 =20~22μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.9±0.

03.

13. The quantitative blood filtration chip according to claim 1, characterized in that: The liquid reservoir has one or more of the following features: (a) When the volume of the reservoir is V 储 =28μL~34μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.75±0.02; (c) When the released volume of filtered blood V 释放 =17~19μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.75±0.02; (e) When the minimum sample volume V 样品 =17~19μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.75±0.

02.

14. The quantitative blood filtration chip according to claim 1, characterized in that: The liquid reservoir has one or more of the following features: (b) When the volume of the reservoir is V 储 =38~42μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.8~1.0; (c) When the released volume of filtered blood V 释放 =17.5~18.5μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.1~0.8; (d) When the released volume of filtered blood V 释放 =20~21μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.8~1.0; (e) When the minimum sample volume V 样品 =17.5~18.5μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.1-0.8; and / or (f) When the minimum sample volume V 样品 =20~21μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.8~1.

0.

15. The quantitative blood filtration chip according to claim 1, characterized in that: The liquid reservoir has one or more of the following features: (b) When the volume of the reservoir is V 储 =38~42μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.9±0.05; (c) When the released volume of filtered blood V 释放 =17.5~18.5μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.6~0.8; (d) When the released volume of filtered blood V 释放 =20~21μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.9±0.05; (e) When the minimum sample volume V 样品 =17.5~18.5μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.6~0.8; and / or (f) When the minimum sample volume V 样品 =20~21μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.9±0.

05.

16. The quantitative blood filtration chip according to claim 1, characterized in that: The liquid reservoir has one or more of the following characteristics: (b) When the volume of the reservoir is V 储 =38~42μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.9±0.03; (c) When the released volume of filtered blood V 释放 =17.5~18.5μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.75±0.05; (d) When the released volume of filtered blood V 释放 =20~21μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.9±0.03; (e) When the minimum sample volume V 样品 =17.5~18.5μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.75±0.05; and / or (f) When the minimum sample volume V 样品 =20~21μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.9±0.

03.

17. The quantitative blood filtration chip according to claim 1, characterized in that: The liquid reservoir has one or more of the following characteristics: (c) When the released volume of filtered blood V 释放 =17.5~18.5μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.75±0.02; (e) When the minimum sample volume V 样品 =17.5~18.5μL, the ratio of the diameter of the bottom of the reservoir to the height of the reservoir D 储 / H 储 =0.75±0.

02.

18. The quantitative blood filtration chip according to claim 1, characterized in that: The diameter D of the bottom surface of the reservoir 储 Larger than 2 to 10 mm.

19. The quantitative blood filtration chip according to claim 1, characterized in that: The diameter D of the bottom surface of the reservoir 储 =3~10mm.

20. The quantitative blood filtration chip according to claim 1, characterized in that: The diameter D of the bottom surface of the reservoir 储 =3~5mm.

21. The quantitative blood filtration chip according to claim 1, characterized in that: The diameter D of the bottom surface of the reservoir 储 =3.4~5mm.

22. The quantitative blood filtration chip according to claim 1, characterized in that: The bottom surface of the liquid storage tank is a bottom surface treated by hydrophilic modification.

23. The quantitative blood filtration chip according to claim 1, characterized in that: The blood filtering mechanism comprises: a blood inlet (21), wherein the blood inlet is used to add blood to be filtered; A blood filter membrane cavity (22), wherein the blood filter membrane cavity is used to accommodate the blood filter membrane; A collection chamber, the collection chamber is used to collect filtered blood, and the collection chamber comprises a main chamber (27) and a support structure (24) for supporting a blood filter membrane (23); and A blood filtration outlet (26) is fluidically connected to the liquid storage mechanism.

24. The quantitative blood filtration chip according to claim 5, characterized in that: The blood filtering mechanism also includes a blood filtering membrane (23) pre-placed therein.

25. The quantitative blood filtration chip according to claim 1, characterized in that: The indicating mechanism comprises an indicating groove (52) and a second microchannel (51), and at least a portion of the indicating groove and / or the second microchannel is transparent.

26. The quantitative blood filtration chip according to claim 1, characterized in that: The chip further comprises: a pressurizing mechanism (4); the pressurizing mechanism is used to apply external force to the liquid reservoir, so that the filtered blood in the liquid reservoir flows out of the chip body through the liquid reservoir outlet.

27. The use of the quantitative blood filtration chip according to claim 1, characterized in that: Used to filter whole blood and quantitatively obtain plasma.

28. A kit, characterized in that The kit comprises the quantitative blood filtration chip as claimed in claim 1.

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