Test strips

Abstract

The present invention discloses a test strip, comprising a base plate, a sample application area, a color development area, and a transfer layer for transporting a liquid sample from the sample application area to the color development area, wherein the transfer layer comprises a free section and a fixed section, a support element is arranged below the transfer layer so that the free section of the transfer layer is not attached to the base plate, the fixed section of the transfer layer is fixedly connected to the base plate, and at least a portion of the free section is inserted into a first gap between the enzyme layer and the base plate and contacts the lower surface portion of the enzyme layer. The test strip of the present invention has a simple structure and a small volume, can be tested at any time with a portable analyzer, can quickly and accurately obtain test results, has a small difference in the detection performance of the test strip, and has good consistency and high accuracy in the detection results.

Description

Technical Field

[0001] The present invention belongs to the technical field of in vitro diagnosis, and in particular relates to a test strip and an application thereof. Background Art

[0002] Clinically, diseases are diagnosed by testing the content or presence of a certain component (analyte) in samples such as blood, urine, and saliva.

[0003] Dry test strips are one of the commonly used detection methods in clinical practice. This type of portable test strips or test cards are disposable and will not cause cross contamination. They are also easy to operate and quick to detect. The test results of the test strips can be directly visually inspected, or tested on-the-go with a portable analyzer, so that doctors and patients can quickly and accurately obtain test results and take timely measures to prevent and reduce disease risks.

[0004] Currently, common dry test strips include lateral flow test strips, vertical flow test strips, or test strips with both lateral flow and vertical flow. The detection principle can adopt chemical method, immunoassay, electrochemical method, or a combination of them. According to the purpose of the test, it can be divided into quantitative test and qualitative test. The analytes in the sample can be respiratory pathogens, digestive tract pathogens, metabolic hormones, blood sugar, blood lipids, urea, uric acid, creatinine, etc. related to chronic diseases, tumor markers, biochemical specific proteins such as C-reactive protein, homocysteine, etc., allergens, myocardial markers such as myocardial enzymes, troponin and myoglobin, drug abuse such as morphine, etc.

[0005] Lateral cross-flow test strips generally include a base plate, on which a sample pad, a marking pad, a detection pad and a water-absorbing pad are arranged one after another in sequence from upstream to downstream. The liquid sample dripped on the sample pad flows through the sample pad, the marking pad, the detection pad and the water-absorbing pad in sequence. The detection pad in the current lateral cross-flow test strip is pasted flatly on the base plate to play a role in liquid transfer. After the detection is completed, the depth of the color of the test area on the detection pad is linearly related to the concentration of the analyte in the sample to be detected, thereby judging the level of the corresponding analyte in the sample. For example, a vertical flow test strip generally includes a base plate, on which a sample pad, a separation pad and a detection pad are arranged in sequence from top to bottom, and an observation hole is opened at the detection pad of the base plate. Dry test strips can also be provided with a variety of test strips in the form of test pads at intervals on the base plate, such as urine joint test strips. Dry test strips can be used directly for detection, or the test strips can be assembled into a box body for detection as needed.

[0006] U.S. Patent No. 4,876,067 uses a dry chemical test strip that combines lateral cross flow and vertical flow. During the test, the sample is added to the plasma separation layer, flows through the reagent pretreatment layer to the transfer layer, and the transfer layer transfers the treated sample to the detection area; after adding the sample, the analyzer presses down the transparent covering film, and the reagent layer contacts the transfer layer, thereby generating a detectable color signal. The transfer layer of the test strip is flatly pasted on the bottom plate, the separation layer and the reagent pretreatment layer are located on one end of the transfer layer, and the reagent layer and the covering film are located on the other side of the separation layer and the reagent pretreatment layer, and do not contact the transfer layer before adding the sample. U.S. Patent No. 5,302,346 also has a similar structure, and a mesh protective layer is provided above the separation layer of the test strip.

[0007] Existing test strips measure the content of analytes in blood samples. For example, when measuring the content of alanine aminotransferase (ALT) in a blood sample, the detection performance of different test strips varies greatly and the consistency is poor. Summary of the invention

[0008] The present invention overcomes the defects of the prior art. The present invention improves the performance of the test paper by improving the structure of the test paper. The test paper of the present invention includes a base plate, and a sample adding area and a color developing area are set on the base plate. The sample adding area and the color developing area are not in direct contact with each other. The transfer layer located on the base plate transfers the components of the sample adding area to the color developing area, wherein the sample adding area includes an enzyme layer, and there is a first gap between the enzyme layer and the base plate. The color developing area includes a color developing layer, and there is a second gap between the color developing layer and the base plate. The transfer layer includes a free section and a fixed section. A supporting element is arranged below the transfer layer so that the free section of the transfer layer is not attached to the base plate. The fixed section of the transfer layer is fixedly connected to the base plate, and at least a part of the free section is inserted into the first gap between the enzyme layer and the base plate and contacts the lower surface portion of the enzyme layer. Wherein, the fixed section of the transfer layer can be directly or indirectly fixedly connected to the base plate.

[0009] Further, the supporting element is located below the free section of the transmission layer.

[0010] Furthermore, the free section of the transfer layer is tilted upward toward the enzyme layer.

[0011] Further, the supporting element is located below the fixed section of the transmission layer.

[0012] Furthermore, the sample adding area also includes a covering layer, a sample suction layer, a substrate layer, and a whole blood separation layer. The outer edges of the covering layer, the sample suction layer, the substrate layer, the whole blood separation layer, and the enzyme layer in the same direction are fixed to the bottom plate from top to bottom through the first adhesive element.

[0013] Furthermore, one end of the color development layer away from the sample application area is connected to the bottom plate through a second adhesive element.

[0014] Furthermore, the test strip is used to detect alanine aminotransferase.

[0015] Furthermore, the enzyme layer comprises pyruvate oxidase and peroxidase.

[0016] Furthermore, the substrate layer contains L-alanine.

[0017] Furthermore, the color developing layer comprises α-ketoglutaric acid and an indicator on the side facing the base plate.

[0018] The test strip of the present invention is provided with a supporting element below the transfer layer, so that one end (free section) close to the enzyme layer is not connected to the bottom plate, and compared with the existing test strips, the contact area between the free section of the transfer layer and the enzyme layer in the sample application area is reduced, so that the direction and position of sample flow diffusion can be effectively controlled, which is conducive to the uniform diffusion of samples and reactants on the transfer layer (NC membrane). The difference in detection performance of different test strips is small, the consistency of the detection results of the test strips is good, and the accuracy of the test results is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of the front side of the test strip of the control group in Example 4.

[0020] Figure 2 yes Figure 1 A three-dimensional image of the test strip.

[0021] Figure 3 It is a structural diagram of the front side of the test strip in Example 1.

[0022] Figure 4 yes Figure 3 A three-dimensional image of the test strip.

[0023] Figure 5 It is a structural diagram of the front side of the test strip in Example 2.

[0024] Figure 6 yes Figure 5 A three-dimensional image of the test strip.

[0025] Figure 7 It is a schematic diagram of the test strip being inserted into the analyzer, with the optical sampling element of the analyzer not pressed against the color developing layer.

[0026] Figure 8 It is a schematic diagram of the test strip being inserted into the analyzer and the optical sampling element of the analyzer being pressed against the color developing layer.

[0027] Fig. 9 It is a linear graph of the whole blood test results of Example 6.

[0028] Fig.10 It is a linear graph of the plasma test results of Example 6. DETAILED DESCRIPTION

[0029] The present invention will be described in detail below with reference to the accompanying drawings.

[0030] A test paper comprises a sample adding area 1, a color developing area 2, and a transfer layer 3 for transporting a liquid sample from the sample adding area 1 to the color developing area 2 (result display area), wherein the transfer layer 3 is fixed on a bottom plate 4.

[0031] The sample adding area 1 is provided with a reagent layer, which may be a single layer or multiple layers superimposed on each other. A gap is provided between the reagent layer in the sample adding area and the bottom plate. The color developing area 2 is provided with a color developing layer, and a reagent is provided on the side of the color developing layer facing the bottom plate 4. A gap is provided between the color developing layer and the bottom plate.

[0032] The transfer layer 3 includes a free section 31 and a fixed section 32. A support element 12 is provided below the transfer layer so that the free section 31 of the transfer layer is not attached to the bottom plate, and the fixed section 32 of the transfer layer is fixedly connected to the bottom plate. At least a portion of the free section 31 is inserted into the gap between the reagent layer in the sample loading area and the bottom plate, and contacts a portion of the lower surface of the reagent layer at the bottom of the sample loading area.

[0033] When the test strip is in a non-testing state, a certain distance is maintained between the color developing layer 11 and the transfer layer 3, and the color developing layer 11 does not contact the transfer layer 3. When the test strip is in a testing state, the sample added to the sample adding area and the reagent in the sample adding area form a mixture that flows into the transfer layer 3, the color developing layer 11 is pressed down and contacts the transfer layer 3, and the reagent on the color developing layer contacts the mixture on the transfer layer 3 and reacts to obtain the test result.

[0034] Example 1 Alanine aminotransferase test strip (ALT test strip)

[0035] Alanine aminotransferase (ALT), which catalyzes the amino transfer between alanine and α-ketoglutarate to form pyruvate and glutamate, is an important metabolic enzyme and the most commonly used indicator of liver damage.

[0036] The reaction principle of the alanine aminotransferase test strip is as follows:

[0037]

[0038] like Figure 3 and Figure 4 As shown, the ALT test paper of the present invention comprises a bottom plate 4, on which a sample adding area 1 and a color developing area 2 are arranged, the sample adding area 1 and the color developing area 2 are not in direct contact with each other, and a transfer layer 3 adhered to the bottom plate 4 transfers the components of the sample adding area 1 to the color developing area 2. The reagent and sample in the sample adding area 1 are transported to the color developing area 2 through the transfer layer 3, and the reaction result of the sample and the reagent is presented in the color developing area 2, and the analyzer reads the color change information of the color developing area to give the test result.

[0039] like Figure 3 and Figure 4 As shown, the sample adding area 1 includes a cover layer 5, a sample suction layer 6, a substrate layer 7, a whole blood separation layer 8 and an enzyme layer 9 stacked together from top to bottom. The outer edges of the cover layer 5, the sample suction layer 6, the substrate layer 7, the whole blood separation layer 8 and the enzyme layer 9 in the same direction are fixed to the bottom plate 4 by a first adhesive element 10. There is a first gap 14 between the enzyme layer 9 located at the bottom layer and the bottom plate 4. In order to ensure the space of the first gap 14 between the enzyme layer 9 and the bottom plate 4, the material of the enzyme layer has a certain rigidity, so that there is a certain distance between the enzyme layer and the bottom plate in the absence of external mechanical pressure; or the enzyme layer 9 starts to tilt upward from the first adhesive element 10, so that there is a certain distance between the enzyme layer and the bottom plate in the absence of external mechanical pressure.

[0040] The covering layer 5 at the top is a mesh structure, which is used to help the blood sample dripped thereon to spread in the sample addition area. The material of the covering layer is selected from but not limited to polyester, nylon, polypropylene, etc. In this embodiment, polyester (SAATI company, model 03-35K-400) is selected.

[0041] The sample absorbing layer 6 is located below the cover layer 5 and is used to absorb and store the blood sample so that the blood sample is slowly released. In this embodiment, the material of the sample absorbing layer 6 is selected from but not limited to glass fiber, polyester, etc. In this embodiment, glass fiber (Hangzhou Jinyi Biotechnology Co., Ltd., model T8964) is selected.

[0042] The substrate layer 7 is located below the sample suction layer 6, and the substrate layer 7 contains a substrate required for the detection reaction of glutamic alanine transaminase. In this embodiment, the substrate layer 7 is treated with reagent 2, and the reagent 2 includes L-alanine 5% w / w, a buffer and a non-reactant, wherein the buffer and the non-reactant are 50mmol K-PBS with a pH value of 8.5 and an erythrocyte antibody. The material of the substrate layer is selected from but not limited to filter paper, glass fiber, etc., and filter paper (Hangzhou Special Paper Co., Ltd., model A thickness 0.1mm) is selected in this embodiment.

[0043] The whole blood separation layer 8 (also called blood filter membrane) is located below the substrate layer 7. The whole blood separation layer 8 is used to filter red blood cells and separate serum / plasma. The separated serum / plasma continues to flow downward to the enzyme layer 9. The material of the whole blood separation layer 8 can be selected from but not limited to glass fiber, cotton fiber, a mixed material of glass fiber and cotton fiber, etc. This embodiment uses glass fiber, cotton fiber, a mixed material of glass fiber and cotton fiber, polyethersulfone, etc. This embodiment uses a mixed material of glass fiber and cotton fiber (Glass Statement Technology (Shanghai) Co., Ltd., model 8121-6621).

[0044] The enzyme layer 9 at the bottom contains the enzyme required for the alanine aminotransferase detection reaction. In this embodiment, the enzyme layer 9 is treated with reagent 3, which includes 125U / ml of pyruvate oxidase, 0.4% w / w of thiamine pyrophosphate, 0.01% w / w of flavin adenine dinucleotide, 500U / ml of peroxidase, buffer (100mmol K-PBS, pH 8.5) and non-reactants 92.8% w / w (non-reactants include sugars (2% trehalose), inorganic salts (0.1% MgCl2) and 1.5% of surfactant S-24). The material of the enzyme layer can be selected from but not limited to filter paper, polyethersulfone, etc. In this embodiment, filter paper (Hangzhou Special Paper Co., Ltd., model A thickness 0.1mm) is selected.

[0045] The color development area 2 includes a color development layer 11, and one end of the color development layer 11 away from the sample application area is connected to the bottom plate 4 through a second adhesive element 15. The second adhesive element 15 has a certain height so that a second gap 16 is provided between the color development layer 11 and the bottom plate 4. The material of the color development layer 11 has a certain rigidity. In the absence of external mechanical pressure, the color development layer 11 will not bend downward to contact the transfer layer 3, and a certain distance is maintained between the color development layer 11 and the transfer layer 3. The material of the color development layer 11 is selected from but not limited to a transparent or translucent plastic sheet (Tekra Corporation, model Makrofol DE 6-2).

[0046] In this embodiment, a reaction reagent (reagent 4) is coated on the side of the color development layer 11 facing the base plate 4, and the reaction reagent includes a reaction substrate and a color developer, specifically, a reaction substrate 1% w / w α-ketoglutaric acid and a color developer 0.8% w / w 4-aminoantipyrine.

[0047] The transfer layer 3 includes a free section 31 and a fixed section 32. The free section 31 is not attached to the bottom plate 4, and the free section 31 does not contact the bottom plate 4 in the absence of external mechanical pressure. The fixed section 32 is attached to the bottom plate 4. At least a portion of the free section 31 is inserted into the first gap 14 between the enzyme layer 9 and the bottom plate 4 and is located below the enzyme layer 9. The raised front edge 311 of the free section 31 can contact the lower surface of the enzyme layer 9.

[0048] A support element 12 is also fixedly disposed on the bottom plate. In one embodiment, the support element 12 is located below the free section 31 of the transfer layer and in the first gap 14 between the enzyme layer 9 and the bottom plate 4. In a further embodiment, the support element 12 is also located in the first gap 14 between the enzyme layer 9 and the bottom plate 4. The support element 12 is bonded to the bottom plate, and the support element 12 has a certain height so that the free section 31 of the transfer layer 3 overlapped thereon is tilted upward. In this embodiment, the support element 12 is located at the front end of the free section 31 of the transfer layer.

[0049] The transfer layer fixed section 32 or most of the fixed section 32 is located at the second gap 16 between the color development layer 11 and the base plate 4, and in the absence of external mechanical pressure, the color development layer 11 will not bend downward to contact the transfer layer fixed section 32, and there is a certain distance between the color development layer 11 and the transfer layer 3.

[0050] The material of the transfer layer 3 is selected from, but not limited to, NC film, etc. In this embodiment, the transfer layer uses NC film (GlobalLife Sciences Technologies (shanghai) Co., LTD, model 80HP), and the transfer layer is treated with a reagent 5, wherein the reagent includes S-24 with a concentration of 0.2% (mass ratio). The material of the support element 12 is selected from, but not limited to, materials that are not easily deformed, such as polyethylene terephthalate (PET), and in this embodiment, PET (DuPont, model Melinex ST328) is selected.

[0051] The preparation of alanine aminotransferase test strip comprises the following steps:

[0052] Prepare the reagents needed for the test strips.

[0053] Reagent 2 (reagent on substrate layer) includes L-alanine 5% w / w, 50 mmol K-PBS pH 8.5, and red blood cell antibody.

[0054] Reagent 3 (reagent on the enzyme layer) includes pyruvate oxidase 125 U / ml, thiamine pyrophosphate 0.4% w / w, flavin adenine dinucleotide 0.01% w / w, peroxidase 500 U / ml, 100 mmol K-PBS pH 8.5, and non-reactants 92.8% w / w, the non-reactants including 2% trehalose, 0.1% MgCl2 and 1.5% surfactant S-24.

[0055] Reagent 4 (reaction reagent on the color development layer) includes reaction substrate α-ketoglutaric acid 1% w / w and indicator 0.8% w / w 4-aminoantipyrine.

[0056] Reagent 5 (reagent on the transfer layer) included S-24 at a concentration of 0.2% by weight.

[0057] Preparation of transfer layer 3: soak the NC membrane in reagent 5, take out the filter paper after soaking, remove the excess reagent on the surface of the filter paper, and then dry it in an oven at 55°C.

[0058] Preparation of substrate layer 7: Soak filter paper in reagent 2, take out the filter paper after soaking, remove excess reagent on the surface of the filter paper, and then dry it in an oven at 55°C.

[0059] Preparation of enzyme layer 9: Soak filter paper in reagent 3, take out the filter paper after soaking, remove excess reagent on the surface of the filter paper, and then dry it in an oven at 55°C.

[0060] Preparation of color development layer 11: Spray reagent 4 solution evenly on a frosted plastic sheet and let it dry naturally.

[0061] Assembly of the test strip: stick the support element 12 at the preset position of the bottom plate 4, and then stick the transfer layer 3 at the preset position of the bottom plate 4, wherein the free section 31 of the transfer layer overlaps the support element 12, and the fixed section 32 of the transfer layer is glued to the bottom plate 4, and the covering layer 5, the sample suction layer 6, the substrate layer 7, the whole blood separation layer 8 and the enzyme layer 9 are stacked from top to bottom at the preset position of the bottom plate 4, and the first adhesive element 10 is used to fix them on the bottom plate 4 on the same outer side of each layer, and the raised free section 31 of the transfer layer 3 is inserted under the enzyme layer at the first gap 14 between the enzyme layer 9 and the bottom plate 4, and the raised front edge 311 of the free section 31 contacts with a part of the lower surface of the enzyme layer 9, and the free section 31 of the transfer layer 3 overlaps the support element 12, and it is necessary to make the free section 31 contact the bottom of the enzyme layer 9, so as to make a semi-finished large card of the test strip, and then use a rolling cutter to cut the semi-finished large card of the test strip into Figure 4 The single test paper shown has a certain width. In this embodiment, the width of the single test paper is 6 mm.

[0062] The length and width of the covering layer 5, the sample absorbing layer 6, the substrate layer 7, the whole blood separation layer 8 and the enzyme layer 9 are 5 mm and 6 mm respectively, the length and width of the color developing layer 11 are 25 mm and 6 mm respectively, the length and width of the bottom plate 4 are 80 mm and 6 mm respectively, the length and width of the transfer layer 3 are 17 mm and 6 mm respectively, and the front end of the free section 31 of the transfer layer 3 overlaps the lower surface of the enzyme layer 9 by about 1-4 mm. In this embodiment, the front end of the free section 31 of the transfer layer 3 overlaps the lower surface of the enzyme layer 9 by about 2 mm-3 mm. The length direction refers to the longitudinal direction of the test paper from the sample application area 1 to the color developing area 2, and the width refers to the direction perpendicular to the longitudinal direction of the test paper.

[0063] Example 2

[0064] like Figure 5 and Figure 6 Shown is another design of the ALT test strip of the present invention. Figure 5 and Figure 6 The test strip shown is the same as the test strip of Example 1 ( Figure 3 and Figure 4The difference compared with the test strip of the present embodiment is that the support element 12 of the test strip of the present embodiment is not located below the enzyme layer, and in a further embodiment, the support element 12 is not located in the sample application area. In some embodiments, the support element is located in the color development area, and in other embodiments, the support element is located at the fixed section 32 in the color development area.

[0065] like Figure 5 and Figure 6 The test strip shown includes a bottom plate 4, on which a sample application area 1 and a color development area 2 are arranged. The sample application area 1 and the color development area 2 are not in direct contact with each other, and a transfer layer 3 adhered to the bottom plate 4 transfers the components of the sample application area 1 to the color development area 2. The sample application area 1 includes a cover layer 5, a sample absorption layer 6, a substrate layer 7, a whole blood separation layer 8 and an enzyme layer 9 stacked together from top to bottom, and each layer is fixed to the bottom plate 4 by a first adhesive element 10. The color development area 2 includes a color development layer 11, and one end of the color development layer 11 away from the sample application area is connected to the bottom plate 4 by a second adhesive element 15.

[0066] The transfer layer 3 includes a free section 31 and a fixed section 32, and the free section 31 is not attached to the bottom plate 4, that is, the free section 31 is not in contact with the bottom plate 4. At least a portion of the free section 31 of the transfer layer 3 is inserted into the first gap 14 between the enzyme layer 9 and the bottom plate 4, and the front edge 311 of the free section 31 is in contact with a portion of the lower surface of the enzyme layer 9. In this embodiment, the front end of the free section 31 of the transfer layer 3 overlaps the lower surface of the enzyme layer 9 by about 2 mm to 3 mm.

[0067] A support element 12 is provided between the fixed section 32 and the bottom plate 4, the support element 12 is located in the color development area 2, and the front edge of the support element does not extend to the sample addition area 1. The support element 12 is located below the fixed section 32 of the transfer layer 3, the fixed section 32 is adhered to the support element, and the support element 12 is adhered to the bottom plate 4.

[0068] Example 3

[0069] like Figure 7 and Figure 8 The figure shows the detection process of alanine aminotransferase in a sample using an analyzer and a test strip. The analyzer includes an optical sampling element 13, which can act as a pressing block and can press down on the display layer 11 and bend it down to contact the transmission layer 3. Figure 4 or Figure 6The test strip shown is put into the analyzer, and the sample to be tested is added to the cover layer 5 of the sample adding area of ​​the test strip. The sample penetrates into the enzyme layer 9 through the cover layer 5, the sample absorbing layer 6, the substrate layer 7, and the whole blood separation layer 8. The sample and reagent reaching the enzyme layer are transferred to the transfer layer 3. As the optical sampling element 13 of the analyzer moves downward and presses onto the color development layer 11, the analyzer sampling element 13 moves further downward, and the color development layer 11 is bent downward by the mechanical pressure of the sampling element 13 and contacts the transfer layer 3. The reagent on the color development layer 11 is dissolved by the sample on the transfer layer 3 and contacts the sample and other reagents flowing onto the transfer layer 3, triggering a color reaction. The optical system of the analyzer reads the color change and obtains the test result.

[0070] Example 4 Performance comparison of test strips

[0071] Experimental Group 1: The test strip of Example 1 was used, wherein the height of the support element 12 was selected from 0.2 mm, 0.3 mm and 0.4 mm, respectively labeled as Experimental Group 1-1, Experimental Group 1-2, Experimental Group 1-3 in Table 1. The transfer layer 3 had about 2 mm of film overlapped below the enzyme layer 9.

[0072] Experimental Group 2: The test strip of Example 2 was used, wherein the height of the support element was selected from 0.1 mm, 0.2 mm and 0.3 mm, respectively labeled as Experimental Group 2-1, Experimental Group 2-2 and Experimental Group 2-3 in Table 2. The transfer layer 3 had about 2 mm of film overlapped below the enzyme layer 9.

[0073] Control group: The test strips for the control group are as follows Figure 1 and Figure 2 As shown, the test strip of the control group is basically the same as Example 1 or Example 2, except that the test strip of the control group does not have the supporting element 12, the transfer layer 3 is pasted on the base plate 4, the front end of the transfer layer 3 is fully covered by the enzyme layer 9, and the rear section of the transfer layer is located between the gap between the color development layer and the base plate.

[0074] The plasma samples were tested with the test strips of the experimental group 1 and the control group. The concentrations of ALT in the plasma samples were 40U / L and 160U / L, respectively. The experimental results are shown in Table 1.

[0075] The plasma samples were tested with the test strips of the experimental group 2 and the control group. The concentrations of ALT in the plasma samples were 40U / L and 160U / L, respectively. The experimental results are shown in Table 2.

[0076] Table 1 Experimental results of experimental group 1

[0077]

[0078] Table 2 Experimental results of experimental group 2

[0079]

[0080] CV coefficient of variation, also known as "coefficient of dispersion", is the ratio of the standard deviation of the original data to the average of the original data. The CV value can objectively compare the degree of dispersion of two sets of data. A small CV value indicates that the detection performance of different test strips is slightly different and the consistency is good.

[0081] From the test results, the CV values ​​of the test results of experimental group 1 and experimental group 2 are better than those of the control group without support elements. The CV value of the test paper for the support element height of experimental group 1 is relatively better when 0.4mm is selected.

[0082] Example 5 Precision and Accuracy Test of Test Paper

[0083] Experimental group 3: The test paper of experimental group 1 in Example 4 with a supporting element thickness of 0.4 mm was selected.

[0084] Control group: select the test strip of the control group in Example 4.

[0085] The ALT content in the whole blood samples was measured using the test strips of the experimental group 3 and the control group. The ALT concentrations in the whole blood samples were 10U / L, 40U / L, 80U / L and 160U / L, respectively. The experimental results are shown in Table 3.

[0086] The ALT content in the plasma samples was measured using the test strips of the experimental group 3 and the control group. The ALT concentrations in the plasma samples were 10U / L, 40U / L, 80U / L and 160U / L, respectively. The experimental results are shown in Table 4.

[0087] Table 3 Whole blood test results

[0088]

[0089] Table 4 Plasma test results

[0090]

[0091] The biochemical analyzer reference value refers to the concentration of alanine aminotransferase (ALT) in a whole blood sample tested by a biochemical analyzer, and is used as a standard to judge the accuracy of the test results of the test strip. The biochemical analyzer in this example is the HITACHI manufacturer and model 7100.

[0092] The deviation percentage is the ratio of the deviation to the reference value of the biochemistry analyzer.

[0093] The criteria for judging whether the test paper is qualified are:

[0094] Precision: CV<8.0%.

[0095] Accuracy: ALT <40U / L (<0.68µkat / L), deviation is within ±6U / L (±0.10µkat / L); ≥40U / L, ≤500 U / L (≥0.68µkat / L, ≤8.50µkat / L), deviation is within ±15%.

[0096] From the test results, it can be seen that the detection precision and accuracy of the test paper of the present invention are better than those of the control group.

[0097] Example 6 Linearity Experiment

[0098] The test strip of experimental group 1 in Example 4 with a support element thickness of 0.4 mm was used to measure the ALT content in the whole blood sample and perform linear experimental analysis. The experimental results are shown in Tables 5 and Fig. 9 .

[0099] The test strips of Experimental Group 1 in Example 4 with a support element thickness of 0.4 mm were used to measure the ALT content in the plasma sample and perform linear experimental analysis. The experimental results are shown in Tables 6 and Fig.10 .

[0100] Table 5 Linearity test results using whole blood as sample

[0101]

[0102] Table 6 Linearity test results using plasma as sample

[0103]

[0104] from Fig. 9 and Fig.10 From the test results of the linear experiment, it can be seen that the test paper of the present invention has good linearity and sensitivity.

Claims

1. A test paper, comprising a bottom plate, a sample adding area and a color developing area are arranged on the bottom plate, the sample adding area and the color developing area are not in direct contact with each other, and a transfer layer located on the bottom plate transfers the components of the sample adding area to the color developing area, characterized in that: The sample loading area includes an enzyme layer, and there is a first gap between the enzyme layer and the bottom plate. The color development area includes a color development layer, and there is a second gap between the color development layer and the bottom plate. The transfer layer includes a free section and a fixed section. A supporting element is arranged below the transfer layer so that the free section of the transfer layer is not adhered to the bottom plate. The fixed section of the transfer layer is fixedly connected to the bottom plate. At least a part of the free section is inserted into the first gap between the enzyme layer and the bottom plate and contacts with the lower surface portion of the enzyme layer.

2. The test paper according to claim 1, characterized in that The support element is located below the free section of the transmission layer.

3. The test paper according to claim 2, characterized in that: The free section of the transfer layer is tilted upward toward the enzyme layer.

4. The test paper according to claim 1, characterized in that: The support element is located below the fixed section of the transfer layer.

5. The test paper according to claim 1, characterized in that: The sample adding area also includes a covering layer, a sample suction layer, a substrate layer, and a whole blood separation layer. The outer edges of the covering layer, the sample suction layer, the substrate layer, the whole blood separation layer, and the enzyme layer in the same direction are fixed to the bottom plate from top to bottom through the first adhesive element.

6. The test paper according to claim 1, characterized in that: One end of the color development layer away from the sample adding area is connected to the bottom plate through a second adhesive element.

7. The test paper according to claim 5, characterized in that: The test paper is used for detecting alanine aminotransferase.

8. The test paper according to claim 7, characterized in that: The enzyme layer comprises pyruvate oxidase and peroxidase.

9. The test paper according to claim 7, characterized in that: The substrate layer contains L-alanine.

10. The test paper according to claim 7, characterized in that: The color development layer contains α-ketoglutaric acid and an indicator on the side facing the bottom plate.

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