Dry-chemical test paper and test system for quantitatively determining high-density lipoprotein cholesterol content in human whole blood

Abstract

The application relates to the technical field of biochemical detection, and discloses a dry-chemical test paper for quantitatively measuring the high-density lipoprotein cholesterol content of human whole blood, which comprises, from top to bottom, a diffusion layer, a blood filtration layer, a pre-precipitation layer, a precipitation layer, a supplementary precipitation layer and a reaction layer; the pre-precipitation layer is coated with a first reagent, the first reagent contains a precipitant one, the precipitation layer is coated with a second reagent, the second reagent contains a precipitant two, the supplementary precipitation layer is coated with a third reagent, and the third reagent contains a precipitant three; the precipitant one, the precipitant two and the precipitant three are at least one of dextran sulfate, polyethylene glycol 2000, phosphotungstic acid and polyethyleneimine, and the precipitant one, the precipitant two and the precipitant three adopt different formulations. The dry-chemical test paper can realize simple, rapid, high-precision and high-accuracy quantitative measurement of the high-density lipoprotein cholesterol in human whole blood, so as to solve the technical problem that the existing dry-chemical test paper has low detection accuracy and precision.

Description

Technical Field

[0001] This invention relates to the field of biochemical detection technology, and in particular, to a dry chemical test strip and testing system for quantitatively determining the content of high-density lipoprotein cholesterol in human whole blood. Background Technology

[0002] High-density lipoprotein cholesterol (HDL-C) is an important lipoprotein component in the blood. Because it can reverse the transport of cholesterol from peripheral tissues to the liver for metabolism, it has important clinical significance for assessing cardiovascular disease risk and is often referred to as "good cholesterol".

[0003] Currently, common methods for clinical HDL-C testing include ultracentrifugation, precipitation, and homogeneous methods. Among these, precipitation-based detection techniques, especially those using dry chemical test strips, show promising application prospects in primary healthcare settings and home health monitoring due to their ease of operation, lack of complex equipment, and rapid detection. These methods typically utilize specific precipitants to selectively precipitate non-high-density lipoprotein cholesterol (non-HDL-C) components in serum or plasma, and then measure the remaining HDL-C content in the supernatant or reaction zone.

[0004] However, existing dry chemistry test strip methods still face several technical challenges when applied to direct testing of whole blood samples. First, formed elements such as red blood cells and colored substances like hemoglobin in whole blood can significantly interfere with optical detection results, affecting measurement accuracy. Second, to ensure the specificity and completeness of precipitation for non-HDL-C components (especially low-density lipoprotein cholesterol) while avoiding interference from high concentrations of triglycerides and other substances, the efficiency and anti-interference capabilities of the precipitation system need to be optimized. Furthermore, achieving rapid and uniform sample diffusion and ensuring the reaction layer maintains stable catalytic activity and colorimetric efficiency at room temperature is crucial for improving the overall performance of the test strip, particularly in terms of precision, accuracy, and long-term stability. Summary of the Invention

[0005] This invention provides a dry chemical test strip and testing system for quantitatively determining the content of high-density lipoprotein cholesterol in human whole blood. It can achieve simple, rapid, high-precision and high-accuracy quantitative determination of high-density lipoprotein cholesterol in human whole blood, thereby solving the technical problem that existing dry chemical test strips are easily affected by blood cell interference and incomplete precipitation of non-target cholesterol, resulting in low detection accuracy and precision.

[0006] According to one aspect of the present invention, a dry chemical test strip for quantitatively determining the content of high-density lipoprotein cholesterol in human whole blood is provided, comprising a diffusion layer, a blood filtration layer, a pre-precipitation layer, a precipitation layer, a supplementary precipitation layer, and a reaction layer stacked sequentially from top to bottom; the pre-precipitation layer is coated with a first reagent containing a precipitant one, the precipitation layer is coated with a second reagent containing a precipitant two, and the supplementary precipitation layer is coated with a third reagent containing a precipitant three; the precipitant one, precipitant two, and precipitant three are respectively at least one selected from dextran sulfate, polyethylene glycol 2000, phosphotungstic acid, and polyethyleneimine, and the precipitant one, precipitant two, and precipitant three are formulated differently.

[0007] Furthermore, both precipitant one and precipitant two include dextran sulfate, wherein the molecular weight of the dextran sulfate used in precipitant one is greater than that of the dextran sulfate used in precipitant two; precipitant three is one of polyethylene glycol 2000 and polyethyleneimine; the content of precipitant one in the first reagent, the content of precipitant two in the second reagent, and the content of precipitant three in the third reagent are all 0.1wt% to 1wt%.

[0008] Furthermore, magnesium salts are added to both precipitant one and precipitant two. The magnesium salts used are magnesium chloride or magnesium sulfate. The mass ratio of sulfated dextran to magnesium salt is 1:4 to 1:1.

[0009] Furthermore, the sulfated dextran in precipitant one is sulfated dextran 500000.

[0010] Furthermore, the first reagent also includes buffer one and protectant one; buffer one is HEPES buffer or Tris-HCl buffer, with a pH of 7.2 to 7.8 and a concentration of 0.05 mol / L to 0.1 mol / L; protectant one is at least one of trehalose, sucrose, bovine serum albumin, gelatin, and xanthan gum, with a content of 0.1 wt% to 0.5 wt%.

[0011] Furthermore, the sulfated dextran in precipitant two is sulfated dextran 40000.

[0012] Furthermore, the second reagent also includes buffer one and protectant one; buffer one is HEPES buffer or Tris-HCl buffer, with a pH of 7.2 to 7.8 and a concentration of 0.05 mol / L to 0.1 mol / L; protectant one is at least one of trehalose, sucrose, bovine serum albumin, gelatin, and xanthan gum, with a content of 0.1 wt% to 0.5 wt%.

[0013] Furthermore, the precipitant is polyethyleneimine.

[0014] Furthermore, the third reagent also includes buffer one and protectant one; buffer one is HEPES buffer or Tris-HCl buffer, with a pH of 7.2 to 7.8 and a concentration of 0.05 mol / L to 0.1 mol / L; protectant one is at least one of trehalose, sucrose, bovine serum albumin, gelatin, and xanthan gum, with a content of 0.1 wt% to 0.5 wt%.

[0015] Furthermore, the filtration layer is made of glass fiber membrane with a pore size of 2μm to 5μm and a thickness of 50μm to 250μm. The filtration layer is coated with a fourth reagent, which includes buffer II, protective agent II, and anti-RBC antibody. Buffer II is Tris-HCl buffer with a pH of 7.2 to 7.8 and a concentration of 0.05mol / L to 0.1mol / L. Protective agent II is at least one of trehalose, sucrose, bovine serum albumin, gelatin, and xanthan gum, with a content of 0.1wt% to 0.5wt%. The content of anti-RBC antibody is 0.1mg / mL to 0.5mg / mL.

[0016] Furthermore, the material of the reaction layer is one of cotton, polyethersulfone, and acetate fiber synthetic membrane; the pore size of the reaction layer is 0.2μm to 0.8μm, and the thickness is 50μm to 250μm; the reaction layer is coated with a fifth reagent, which includes buffer three, substrate, enzyme, protective agent three, and surfactant; buffer three is HEPES buffer or Tris-HCl buffer, pH 7.2 to 7.8, concentration 0.05mol / L to 0.1mol / L; the substrate is one of 4-aminoantipyrine and 3-methyl-2-benzothiazolinone hydrazone, with a content of 0.1wt% to 1wt%; the enzyme is one of cholesterol esterase, cholesterol oxidase, and peroxidase, with a content of 0.1wt% to 1wt% respectively; the protective agent three is at least one of trehalose, sucrose, bovine serum albumin, gelatin, and xanthan gum, with a content of 0.1wt% to 0.5wt%.

[0017] Furthermore, a base plate is provided on the lower surface of the reaction layer; the dry chemical test paper also includes an upper cover and a lower cover, the upper cover having a sample application hole and the lower cover having a test hole, the upper cover fastening onto the lower cover and the sample application hole and the test hole being arranged vertically correspondingly; by fastening the upper cover and the lower cover, the diffusion layer, blood filtration layer, pre-precipitation layer, precipitation layer, supplementary precipitation layer, reaction layer and base plate are clamped in the cavity enclosed by the upper cover and the lower cover, and the diffusion layer, blood filtration layer, pre-precipitation layer, precipitation layer, supplementary precipitation layer and reaction layer are located in the area corresponding to the sample application hole and the test hole, and the viewing window of the base plate is matched with the test hole.

[0018] According to another aspect of the present invention, a testing system for quantitatively determining the content of high-density lipoprotein cholesterol in human whole blood is also provided, comprising the aforementioned dry chemical test strip for quantitatively determining the content of high-density lipoprotein cholesterol in human whole blood, and a reflectometer; the dry chemical test strip is loaded into the reflectometer, the reflectometer controls the reaction temperature at 37±0.5℃, the measurement wavelength is 630nm, and the light signal is converted into high-density lipoprotein cholesterol concentration through a built-in standard curve.

[0019] The present invention has the following beneficial effects: 1. Synergistic effect of diffusion layer and blood filtration layer: The diffusion layer first receives the whole blood sample, allowing the sample to diffuse rapidly and evenly laterally, avoiding the sample from concentrating in a point-like penetration, thus laying the foundation for the uniformity of subsequent reactions; the blood filtration layer plays a primary filtration role, effectively retaining most of the red blood cells in the whole blood and effectively filtering out colored substances such as hemoglobin, avoiding the interference of colored substances with color development when traditional dry chemical test strips are directly added to whole blood samples, thus improving the accuracy and reliability of whole blood testing.

[0020] 2. Synergistic effect of pre-precipitation layer, precipitation layer, and supplementary precipitation layer: This constitutes a three-step precipitation method. The pre-precipitation layer (first precipitation step) is the first precipitation checkpoint, performing preliminary and rapid precipitation of non-HDL-C components (mainly low-density lipoprotein cholesterol LDL and very low-density lipoprotein cholesterol VLDL) in the blood sample that has penetrated to this step. This removes some interfering substances before the sample enters the core reaction zone, effectively reducing the non-HDL-C load that needs to be processed in the subsequent precipitation process. The precipitation layer (second precipitation step) is the main stage of the precipitation process. After the pre-precipitation layer treatment, the remaining non-HDL-C in the sample reacts with a second precipitant, which is different from the first reagent, using a different mechanism of action. The precipitant is designed to achieve synergistic and specific precipitation of different non-HDL-C subclasses. This staged, multi-formulation design can more thoroughly precipitate various types of non-HDL-C particles, improving the specificity and efficiency of precipitation. It fundamentally avoids falsely high test results caused by incomplete precipitation of non-target cholesterol. The supplementary precipitation layer (third-step precipitation) is the last barrier to ensure complete precipitation. It captures and precipitates residual non-HDL-C components that may have escaped the first two precipitation layers. It can maximize the assurance that almost all cholesterol that finally reaches the reaction layer and participates in the reaction comes from HDL-C, thereby improving the accuracy and precision of the test. In particular, it can effectively reduce measurement errors for borderline samples or samples with abnormal non-HDL-C concentrations.

[0021] 3. The reaction layer provides a pure reaction environment and accurate color development: After three layers of stepwise precipitation, non-HDL-C has been effectively removed from the sample reaching the reaction layer, thus obtaining a relatively pure reaction environment. The cholesterol detection enzyme system (cholesterol esterase, cholesterol oxidase, peroxidase, etc.) can specifically react with HDL-C to produce an enzymatic colorimetric reaction. Because the interfering substances are effectively removed, the specificity of the colorimetric reaction is stronger, and the final color signal has a better correlation with the HDL-C concentration and a wider linear range, thereby achieving highly accurate quantitative determination.

[0022] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0023] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the structure of a dry chemical test strip for quantitative determination of high-density lipoprotein cholesterol in human whole blood, according to a preferred embodiment of the present invention.

[0024] Legend: 100. Diffusion layer; 200. Blood filtration layer; 300. Pre-precipitation layer; 400. Precipitation layer; 500. Supplementary precipitation layer; 600. Reaction layer; 700. Base plate; 800. Top cover; 900. Bottom cover. Detailed Implementation

[0025] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below. Unless otherwise stated, the raw materials and reagents used in the following embodiments are commercially available or can be prepared by known methods.

[0026] like Figure 1As shown, the dry chemical test strip for quantitative determination of high-density lipoprotein cholesterol (HDL-C) in human whole blood in this embodiment includes a diffusion layer 100, a filtration layer 200, a pre-precipitation layer 300, a precipitation layer 400, a supplementary precipitation layer 500, and a reaction layer 600 stacked sequentially from top to bottom. The pre-precipitation layer 300 is coated with a first reagent containing precipitant one; the precipitation layer 400 is coated with a second reagent containing precipitant two; and the supplementary precipitation layer 500 is coated with a third reagent containing precipitant three. Precipitants one, two, and three are each selected from at least one of dextran sulfate, polyethylene glycol 2000, phosphotungstic acid, and polyethyleneimine, and each uses a different formulation. This invention provides a dry chemical test strip for quantitative determination of HDL-C in human whole blood, constructing a multi-layered, staged, sequential precipitation system consisting of a pre-precipitation layer 300, a precipitation layer 400, and a supplementary precipitation layer 500, with each layer using a different precipitant formulation. The diffusion layer 100 first receives the whole blood sample, allowing the sample to spread rapidly and evenly laterally, avoiding the sample from concentrating in a point-like penetration, thus laying the foundation for the uniformity of subsequent reactions. The filtration layer 200 plays a primary filtration role, effectively retaining most of the red blood cells in the whole blood and effectively filtering out colored substances such as hemoglobin. This avoids the problem of colored substances interfering with color development when the whole blood sample is directly added to traditional dry chemical test strips, thus improving the accuracy and reliability of whole blood testing.The pre-precipitation layer 300, precipitation layer 400, and supplementary precipitation layer 500 employ a three-step precipitation method, forming a three-layer progressive precipitation system. The pre-precipitation layer 300 (the first precipitation step) is the first precipitation checkpoint, performing preliminary and rapid precipitation of non-HDL-C components (mainly low-density lipoprotein cholesterol LDL and very low-density lipoprotein cholesterol VLDL) in the blood sample that has penetrated to this layer. This removes some interfering substances before the sample enters the core reaction zone, effectively reducing the non-HDL-C load required for subsequent precipitation processes. The precipitation layer 400 (the second precipitation step) is the main stage of the precipitation process. After treatment in the pre-precipitation layer 300, the remaining non-HDL-C in the sample reacts here with a second precipitant, different from the first reagent, to achieve the desired effect. Using precipitants with specific mechanisms to achieve synergistic and specific precipitation of different non-HDL-C subclasses, this phased, multi-formulation design can more thoroughly precipitate various types of non-HDL-C particles, improving the specificity and efficiency of precipitation. This fundamentally avoids falsely high test results caused by incomplete precipitation of non-target cholesterol. The supplementary precipitation layer 500 (third-step precipitation) is the last barrier to ensure complete precipitation. It captures and precipitates residual non-HDL-C components that may have escaped the first two precipitation layers, maximizing the assurance that almost all cholesterol reaching the reaction layer 600 is derived from HDL-C. This improves the accuracy and precision of the test, especially for borderline samples or samples with abnormal non-HDL-C cholesterol concentrations, effectively reducing measurement errors. Reaction layer 600 provides a pure reaction environment and accurate color development. After three layers of stepwise precipitation, non-high-density lipoprotein cholesterol (HDL-C) has been effectively removed from the sample reaching reaction layer 600, thus obtaining a relatively pure reaction environment. The cholesterol detection enzyme system (cholesterol esterase, cholesterol oxidase, peroxidase, etc.) in this environment can specifically react with HDL-C to produce an enzymatic colorimetric reaction. Because interfering substances are effectively removed, the specificity of the colorimetric reaction is stronger, and the final color signal has a better correlation with the HDL-C concentration and a wider linear range, thereby achieving highly accurate quantitative determination. This invention relates to a dry chemical test strip for the quantitative determination of high-density lipoprotein cholesterol (HDL-C) in human whole blood. Through a step-by-step, multi-level structure of "diffusion / filtration → pre-precipitation → main precipitation → supplementary precipitation → colorimetric reaction," a synergistic effect is achieved. By organically combining physical filtration with multi-stage chemical precipitation, the two core technical challenges of blood cell interference and incomplete / non-specific precipitation of HDL-C in direct whole blood testing are systematically solved. This significantly improves precipitation efficiency and specificity, effectively reduces background interference, and ultimately ensures that the dry chemical test strip can achieve simple, rapid, high-precision, and high-accuracy quantitative determination of HDL-C in human whole blood.

[0027] In this embodiment, both precipitant one and precipitant two include dextran sulfate, wherein the molecular weight of the dextran sulfate used in precipitant one is greater than that used in precipitant two; precipitant three is one of polyethylene glycol 2000 and polyethyleneimine; the content of precipitant one in the first reagent, the content of precipitant two in the second reagent, and the content of precipitant three in the third reagent are all 0.1wt% to 1wt%. The larger the molecular weight of dextran sulfate, the longer its molecular chain, the more developed its spatial network structure, the faster it binds with lipoproteins to form insoluble complexes, and the larger the precipitate aggregates formed; precipitant one uses high molecular weight dextran sulfate as the first line of defense, which can precipitate larger lipoprotein particles in the sample extremely quickly and efficiently, especially some very low density lipoproteins (VLDL), achieving preferential removal of the largest targets, reducing the burden on subsequent fine precipitation stages, and particularly helping to reduce interference from hypertriglyceridemia samples. Precipitant 2 uses lower molecular weight dextran sulfate. Compared to lower molecular weight dextran sulfate, its molecular size is smaller, and its diffusion and reaction kinetics may be different. It can more precisely and specifically target the core precipitation target of lower density lipoprotein (LDL) and some very low density lipoprotein (VLDL) particles. After the pre-precipitation layer 300 is treated with precipitant 1, the use of precipitant 2 of the same type with a smaller molecular weight at this time helps to ensure efficient precipitation of lower density lipoprotein (LDL) and very low density lipoprotein (VLDL) particles while reducing the risk of non-specific adsorption or co-precipitation of HDL, thereby better maintaining the selectivity of the precipitation reaction. Precipitant 3 uses polyethylene glycol 2000 or polyethyleneimine. Polyethylene glycol (PEG) and polyethyleneimine (PEI) are precipitants with different mechanisms of action than dextran sulfate. PEG mainly precipitates lipoproteins by dehydrating them through steric exclusion, while PEI, as a cationic polymer, mainly relies on charge neutralization. By utilizing these different precipitation mechanisms, residual non-HDL-C components such as chylomicrons (CM) that may escape from the first two layers can be captured. This synergistic effect of multiple mechanisms greatly improves the adaptability of the entire precipitation system to differences in individual samples and the thoroughness of precipitation, further ensuring the specificity of the final detection results. The uniform content range of 0.1wt% to 1wt% ensures that each precipitation layer has sufficient effective components to complete its preset precipitation function, avoiding incomplete precipitation due to insufficient concentration. The upper limit of 1wt% limits the excessive use of precipitant. Excessive concentration may cause the reaction layer 600 to become too dense, affecting sample penetration, increasing the risk of non-specific co-precipitation of HDL, or affecting the physical stability and color uniformity of the test strip due to crystallization and other problems. Therefore, the uniform content range achieves the best balance between ensuring precipitation efficiency and maintaining good physicochemical properties of the test strip.By classifying the three-layer stepwise precipitation into fractions based on molecular weight from large to small and partitioning the synergistic mechanism of dextran sulfate and PEG / PEI, and supplementing with optimized uniform concentration control, a logically rigorous and synergistic precipitation system was constructed. This system achieves stepwise, efficient, and highly specific removal of non-HDL cholesterol from whole blood, from rapid coarse precipitation to fine precipitation and then to differentiated supplementary precipitation. This ensures the completeness and specificity of the precipitation and significantly reduces interference with HDL cholesterol, thus laying a solid foundation for achieving highly accurate and precise quantitative determination in the reaction layer 600.

[0028] In this embodiment, magnesium salt is also added to precipitant one and precipitant two. The magnesium salt is magnesium chloride or magnesium sulfate; the mass ratio of dextran sulfate to magnesium salt is 1:4 to 1:1. Dextran sulfate, as a polyanion, requires a cation as a bridge to effectively bind with negatively charged lipoproteins (such as LDL and VLDL) and form an insoluble complex. Magnesium salt (Mg...) 2+ Magnesium salts are added to both the pre-precipitate layer 300 and the precipitate layer 400 to provide the necessary ionic environment for glucan sulfate to perform its precipitation function efficiently. Magnesium ions and glucan sulfate work synergistically to form a complete and effective chemical precipitation system, ensuring that non-high-density lipoprotein cholesterol can be precipitated quickly and stably. A specific mass ratio of 1:4 to 1:1 for dextran sulfate to magnesium salt allows for fine-tuning within this range based on factors such as the molecular weight of the dextran sulfate used and the properties of the test paper carrier. This allows for finding the optimal balance between precipitation efficiency and system compatibility, ensuring effective and controllable precipitation at any specific point within this range. This represents the optimal solution while simultaneously guaranteeing precipitation capacity and maintaining system stability. At the lower limit of 1:4, indicating a relatively high magnesium salt content, sufficient cations in the solution bind to all dextran sulfate molecules and lipoproteins, minimizing incomplete precipitation due to insufficient cations. This effectively prevents falsely high results caused by an imbalance in the precipitant ratio, ensuring the thoroughness and reliability of the precipitation reaction. At the upper limit of 1:1, where the magnesium salt concentration is controlled to a level commensurate with the dextran sulfate concentration, the adverse effects of excessively high cation concentrations are avoided. Excessive magnesium salt (Mg...)... 2+ It may affect the rate of sample diffusion, and may even affect the size of blood cells in whole blood tests, resulting in blood leakage.

[0029] In this embodiment, the dextran sulfate in precipitant one is dextran sulfate 500000. The first reagent also includes buffer one and protectant one; buffer one is HEPES buffer or Tris-HCl buffer, with a pH of 7.2-7.8 and a concentration of 0.05mol / L-0.1mol / L; protectant one is at least one of trehalose, sucrose, bovine serum albumin, gelatin, and xanthan gum, with a content of 0.1wt%-0.5wt%. The use of dextran sulfate 500000 in precipitant one clarifies the specific morphology of the core functional component of the pre-precipitation layer 300. Fixing the use of this specific molecular weight of dextran sulfate ensures that the complex formed with magnesium salt has a constant and reproducible spatial structure and precipitation kinetics, thereby ensuring the intra- and inter-batch consistency and predictability of the precipitation effect on large lipoprotein particles (such as VLDL), providing a basis for achieving stable detection performance. HEPES or Tris-HCl, two excellent biochemical buffer solutions, were chosen to provide a chemically inert microenvironment that does not interfere with the main reaction. A pH range of 7.2-7.8, strictly limiting the pH to a weakly alkaline range (close to physiological pH), provides the optimal pH window for this type of polyanion-based precipitation reaction, ensuring efficient precipitation while avoiding lipoprotein conformational changes or non-specific aggregation that may be caused by extreme pH conditions. This ensures the selectivity of the precipitation reaction, primarily targeting non-HDL-C. A concentration range of 0.05 mol / L-0.1 mol / L achieves an optimal balance between providing sufficient buffer capacity to maintain pH stability and avoiding the impact of excessively high ionic strength on sample permeability or the physical structure of the reaction layer 600, ensuring the stability of reaction conditions and smooth sample fluid performance. The protective agent is at least one of trehalose, sucrose, bovine serum albumin, gelatin, and xanthan gum, with a content of 0.1wt% to 0.5wt%. Trehalose and sucrose mainly act as freeze-drying protectants, stabilizing other components during the drying process. Bovine serum albumin, gelatin, and xanthan gum, in addition to their protective effects, primarily function as thickeners and film-forming agents. Adding these substances during the preparation (sampling and drying) of the test strip helps form a stable and uniformly porous reagent layer matrix, effectively preventing reagent migration and crystallization, and ensuring uniform reagent distribution. A content range of 0.1% to 0.5% ensures both the formation of an effective protective layer and a stable structure, while avoiding an overly dense reaction layer due to excessive macromolecular substances, which could affect the rapid and uniform penetration and filtration of whole blood samples. This achieves an optimized balance between maintaining layer structural stability and ensuring sample permeability.

[0030] In this embodiment, the dextran sulfate in the precipitant two is dextran sulfate 40000. The second reagent also includes buffer one and protectant one; buffer one is HEPES buffer or Tris-HCl buffer, with a pH of 7.2 to 7.8 and a concentration of 0.05 mol / L to 0.1 mol / L; protectant one is at least one of trehalose, sucrose, bovine serum albumin, gelatin, and xanthan gum, with a content of 0.1 wt% to 0.5 wt%. The dextran sulfate in precipitant 2 is dextran sulfate 40000, specifically limiting the core component of precipitant layer 400 to dextran sulfate with a molecular weight of 40,000. This creates a clear molecular weight gradient and functional distinction with the 500,000 molecular weight specification used in preprecipitant layer 300. The smaller molecular weight means shorter molecular chains and different spatial conformations, allowing it to differ from the higher molecular weight specification in terms of "binding affinity and selectivity with medium-sized lipoproteins such as low-density lipoprotein (LDL)". This specific selection ensures that preprecipitant layer 300 can specifically and efficiently precipitate the main target LDL remaining after preprecipitant layer 300 treatment, helping to reduce non-specific effects on high-density lipoprotein. Buffer 1 is HEPES buffer or Tris-HCl buffer, with a pH of 7.2–7.8 and a concentration of 0.05 mol / L–0.1 mol / L. By placing the precipitate layer 400 and the pre-precipitate layer 300 in the same or similar buffer environment, the dissociation or redissolution of the precipitate complex caused by drastic changes in pH or ionic strength when the sample permeates from the pre-precipitate layer 300 to the precipitate layer 400 is avoided, thus ensuring the continuity and stability of the precipitation process; continuing with the sulfated dextran-Mg 2+ The precipitation reaction provides an optimal weakly alkaline pH environment, ensuring the high efficiency and specificity of the precipitation layer 400 reaction. Using a buffer system of the same type and parameters facilitates process control and cost optimization in reagent preparation during test strip production. Protectant one is at least one of trehalose, sucrose, bovine serum albumin, gelatin, and xanthan gum, with a content of 0.1wt%–0.5wt%. Adding a protectant with similar components and amounts to pre-precipitation layer 300 to precipitation layer 400 maintains the porous and uniform physical structure of precipitation layer 400 during drying and storage, ensuring stable and uniform sample penetration and allowing the precipitation reaction to proceed fully and consistently. It also prevents reagent migration or denaturation, ensuring that precipitant two maintains stable chemical activity and precipitation efficiency throughout its shelf life.

[0031] In this embodiment, polyethyleneimine is used as the third precipitant. The third reagent also includes buffer solution one and protectant one; buffer solution one is HEPES buffer or Tris-HCl buffer, with a pH of 7.2-7.8 and a concentration of 0.05 mol / L-0.1 mol / L; protectant one is at least one of trehalose, sucrose, bovine serum albumin, gelatin, and xanthan gum, with a content of 0.1 wt%-0.5 wt%. Polyethyleneimine, a strongly positively charged cationic polymer, relies on charge neutralization for its precipitation mechanism, which is fundamentally different from the anionic dextran sulfate used in the previous two layers, which relies on polyanion-cation bridging. Using polyethyleneimine, through a differentiated mechanism, effectively captures and precipitates residual non-high-density lipoprotein cholesterol components that may be insensitive to or escape from the first two layers of dextran sulfate system due to structural or charge characteristics. This complementary design greatly enhances the adaptability of the entire precipitation system to differences in individual samples and the thoroughness of precipitation, providing a powerful supplement and ultimate guarantee to the precipitation effect of the first two layers. Buffer 1 is HEPES buffer or Tris-HCl buffer, with a pH of 7.2–7.8 and a concentration of 0.05 mol / L–0.1 mol / L. It provides a buffer environment consistent with the preceding and following layers for polyethyleneimine. This pH range ensures that the amino groups in the polyethyleneimine molecules are in a suitable protonated state, thereby maintaining their effective positive charge density and precipitation ability. A stable pH environment can prevent the dissociation of the formed charge-neutralized precipitate under inappropriate acidic or alkaline conditions, ensuring a stable and perfect final supplemental capture effect. The uniform buffer system avoids unpredictable side reactions caused by sudden environmental changes between layers, ensuring the smoothness and consistency of sample permeation and reaction pathways. The protective agent is at least one of trehalose, sucrose, bovine serum albumin, gelatin, and xanthan gum, with a content of 0.1wt% to 0.5wt%. The protective agent is added to the supplementary precipitation layer 500 to maintain the stability of the physicochemical structure of the layer. In particular, for polymers such as polyethyleneimine, the protective agent helps them form a uniform, amorphous film after drying, preventing them from migrating or forming aggregates that are not conducive to the uniform penetration of the sample, thereby ensuring that their precipitation function can be performed stably and reproducibly.

[0032] The dry chemical test strip for quantitative determination of high-density lipoprotein cholesterol in human whole blood in this embodiment uses a combination design of diffusion layer 100 and blood filtration layer 200 to enable rapid and uniform penetration of whole blood samples and effectively filter out colored substances such as hemoglobin. The combination design of a three-layer precipitation structure of pre-precipitation layer 300, precipitation layer 400 and supplementary precipitation layer 500 ensures effective precipitation of non-high-density lipoprotein cholesterol components in blood cholesterol and reduces the interference of triglycerides in high-lipidemia samples. Based on the diffusion layer 100 promoting rapid and uniform distribution of the sample, and with the synergistic effect of blood filtration layer 200 and the three-layer precipitation structure, the interference of non-target substances is reduced, thereby enabling the reaction layer 600 to maintain high colorimetric ability at room temperature. This invention relates to a dry chemical test strip for the quantitative determination of high-density lipoprotein cholesterol (HDL-C) in human whole blood. The synergistic design of the diffusion layer 100 and the blood filtration layer 200 ensures rapid and uniform penetration of the whole blood sample, providing a foundation for the uniformity of subsequent reactions. It effectively filters out endogenous colored substances such as hemoglobin, significantly reducing the interference of the whole blood sample background on the final optical detection. This overcomes the problem of high background interference when traditional test strips are applied directly to whole blood, improving the accuracy and reliability of the detection. Through a multi-stage precipitation system consisting of a pre-precipitation layer 300, a precipitation layer 400, and a supplementary precipitation layer 500, continuous, stepwise, and more thorough selective precipitation of non-HDL-C components is achieved. This progressive design not only enhances the removal of non-target cholesterol but also effectively reduces the interference of high-concentration triglycerides in hyperlipidemic samples on the precipitation process, ensuring the specific detection of HDL-C, thus directly contributing to the improvement of the accuracy and precision of the final test results. The optimized design of the overall layered structure enables efficient integration of sample diffusion, filtration, precipitation, and reaction steps. With the synergistic effect of the blood filtration layer 200 and the three-layer precipitation structure in resisting interference, the sample reaching the reaction layer 600 is effectively purified, reducing the inhibition or consumption of enzyme reagents in the reaction layer 600 by non-target substances. This allows the reaction layer 600 to maintain high colorimetric ability at room temperature, ensuring stable detection signals, rapid reactions, and simple operation with reliable results. It is particularly suitable for point-of-care testing (POCT) applications in primary healthcare institutions. This invention, a dry chemical test strip for quantitative determination of high-density lipoprotein cholesterol in human whole blood, achieves a synergistic effect by constructing a precise layered functional system of "diffusion filtration-gradient precipitation-specific reaction," enabling direct, rapid, highly accurate, and precise detection of human whole blood samples, while also being easy to operate and stable at room temperature.

[0033] In this embodiment, the pre-precipitation layer 300 is made of one of the following materials: cotton, cellulose acetate, mixed cellulose, or glass cellulose. The pore size of the pre-precipitation layer 300 is 0.2 μm to 0.8 μm, and the thickness is 50 μm to 250 μm. When the sample diffuses into the pre-precipitation layer, the non-high-density lipoprotein cholesterol portion binds with the pre-precipitant to form a polymer, providing a pre-precipitation process for subsequent precipitation filtration. By selecting materials with specific protein binding capabilities, such as cotton, cellulose acetate, or mixed cellulose, and controlling the pore size within the microfiltration range of 0.2 μm to 0.8 μm, the non-high-density lipoprotein cholesterol polymer formed after binding with the pre-precipitant in the sample can be effectively captured in its three-dimensional network structure. This avoids the random diffusion of precipitates in the sample solution and achieves a preliminary and organized separation and enrichment effect. The thickness range of 50μm to 250μm provides sufficient space and reaction time for the pre-precipitation reaction, ensuring a more thorough pre-precipitation process. Simultaneously, this structural design allows for smooth and controllable sample flow, avoiding blockage or channeling caused by inappropriate pore size or thickness. This creates favorable hydrodynamic conditions for the smooth and uniform entry of the sample into the subsequent precipitation layer 400, thus ensuring the efficiency and stability of the multi-layer precipitation system. Treating the pre-precipitation layer as an independent and parameter-defined functional layer, together with the subsequent precipitation layer 400 and the supplementary precipitation layer 500, constitutes a multi-stage, progressive precipitation system. This makes the removal of non-target cholesterol more refined and controllable, reducing the risk of errors caused by incomplete precipitation in a single step or the inclusion of target substances in the precipitate, thereby improving the specificity and accuracy of the final detection results. This invention designs specific parameters for the material selection, pore size, and thickness of the pre-precipitation layer 300. By constructing a first-stage pre-precipitation unit with preliminary capture and enrichment functions, it effectively initiates the selective removal process of non-target cholesterol and provides an optimized reaction interface and fluid channel for subsequent precipitation and supplementary precipitation stages. Thus, it serves as a key starting point for the efficient and orderly operation of the entire multilayer precipitation system, jointly ensuring the accuracy and reliability of quantitative detection of high-density lipoprotein cholesterol. Mixed cellulose (MCE) is a filter material, typically composed of a mixture of nitrocellulose (CN) and cellulose acetate (CA).

[0034] Optionally, the pre-precipitated layer is prepared by immersing the material of the pre-precipitated layer in the prepared first reagent for 10-20 seconds and drying it in an oven at 37°C for 30 minutes.

[0035] In this embodiment, the material of the precipitation layer 400 is one of cotton, polyethersulfone, or acetate fiber synthetic membrane; the pore size of the precipitation layer 400 is 0.2μm to 0.8μm, and the thickness is 50μm to 250μm. As the core filtration unit, the precipitation layer 400, using cotton, polyethersulfone, or acetate fiber synthetic membrane materials, combined with a precise pore size of 0.2μm to 0.8μm, forms a highly efficient sieving interface. This allows residual non-high-density lipoprotein cholesterol in the sample flowing out of the pre-precipitation layer 300 to further combine with the precipitant and form polymers, effectively retaining them on the membrane surface. This "deep capture" mechanism compensates for any omissions that may exist in the pre-precipitation stage, ensuring that non-target components are removed more thoroughly. The precipitation layer 400 is designed as an independent and parameter-defined functional layer, forming a multi-level precipitation structure with progressive functions and synergistic complementarity with the pre-precipitation layer 300 and the supplementary precipitation layer 500. In this system, the precipitate layer 400 plays a crucial and decisive role in separation. Its thickness of 50μm to 250μm provides ample space for precipitate retention, preventing rapid clogging and ensuring smooth flow of the sample fluid. This makes the entire separation process more controllable and reliable, reducing the risk of detection errors caused by incomplete single-stage precipitation. Through the efficient filtration of the precipitate layer 400, the retained non-target cholesterol polymers are effectively separated from the liquid stream. This allows the sample liquid that continues to diffuse to the subsequent precipitate layer 500 and reaction layer 600 to undergo further and significant purification. At this point, the content of non-target interfering substances has been greatly reduced, decreasing the total amount of substances that may reach the reaction layer 600 and interfere with the final colorimetric reaction. This creates favorable conditions for the reaction layer 600 to achieve high signal-to-noise ratio specific colorimetric development, thereby improving the accuracy of the final detection results.

[0036] Optionally, the precipitate layer is prepared by immersing the material of the precipitate layer in the prepared second reagent for 10-20 seconds and drying it in an oven at 37°C for 30 minutes.

[0037] In this embodiment, the material of the supplementary precipitate layer 500 is one of cotton, polyethersulfone, and acetate fiber synthetic membrane; the pore size of the supplementary precipitate layer 500 is 0.2μm to 0.8μm, and the thickness is 50μm to 250μm. As the final physical barrier of the multilayer filtration system, the supplementary precipitate layer 500 captures and filters out trace residual substances, especially triglycerides, that may penetrate the preceding precipitate layer 400 and interfere with the final detection. Through its precise pore size of 0.2μm to 0.8μm, it can effectively trap the polymers formed by these interfering substances and the precipitant, preventing them from entering the final reaction layer 600. This reduces the turbidity or chemical interference that high concentrations of triglycerides in hyperlipidemic samples may cause to the colorimetric reaction, broadening the applicability of the test strip for abnormal samples. The supplementary precipitation layer 500, together with the pre-precipitation layer 300 and the precipitation layer 400, forms a progressively refined separation system. As the third-stage separation unit, the supplementary precipitation layer 500 is specifically designed to address any residual trace interferences (such as triglycerides) that may remain after the first two precipitation stages, providing a crucial safeguard. This multi-stage cascade design ensures thorough separation from a system architecture perspective, significantly improving the stability and reliability of test results for samples with different characteristics. After the final precipitation in the supplementary precipitation layer 500, the sample solution reaching the reaction layer 600 is the product of three stages of purification: pre-precipitation, precipitation, and supplementary precipitation. The ratio of the target analyte (HDL-C) to non-target interferences in the sample reaches its maximum, creating an extremely clean background environment for the enzymatic colorimetric reaction in the reaction layer 600. This minimizes non-specific reactions and ensures a high degree of specificity and linearity between the final detection signal (such as color intensity) and the true HDL-C concentration, directly contributing to the accuracy of the final quantitative result.

[0038] Optionally, the preparation of the supplementary precipitate layer is as follows: the material for the supplementary precipitate layer is immersed in the prepared third reagent for 10-20 seconds and dried in an oven at 37°C for 30 minutes.

[0039] In this embodiment, the diffusion layer 100 is made of one of the following materials: nylon mesh, polyethylene mesh, polypropylene mesh, or polyvinyl chloride mesh; the pore size is 20μm to 50μm, and the thickness is 50μm to 250μm. The diffusion layer 100 is made of hydrophobic polymer mesh materials such as nylon, polyethylene, polypropylene, and polyvinyl chloride, which avoids the absorption of plasma water by hydrophilic materials. This characteristic prevents sample concentration in the diffusion layer 100 and avoids cell rupture that may occur due to direct contact between red blood cells and dry hydrophilic materials. This eliminates detection bias caused by changes in sample state at the source and lays the foundation for the accuracy of subsequent steps. The pore size design of 20μm to 50μm promotes rapid sample penetration through capillary forces and also plays a preliminary mechanical sieving role, effectively blocking large particulate impurities that may be present in whole blood. The thickness range of 50μm to 250μm provides sufficient path length for liquid diffusion, ensuring uniform advancement of the liquid front and avoiding channeling or uneven diffusion. At the same time, it avoids excessive penetration resistance caused by excessive thickness. This synergistic design achieves a smooth and uniform transition of the sample from the sample application area to the filtration layer 200. The selected material has good chemical inertness and mechanical strength, and its risk of non-specific adsorption to blood components is low, ensuring the specificity of the test. At the same time, its stable physical properties make it less prone to deformation during storage and transportation, ensuring a tight fit with the lower blood filtration layer 200. This ensures the consistency of diffusion performance between different production batches of test strips and improves the reliability of the product.

[0040] In this embodiment, the material of the blood filtration layer 200 is a glass fiber membrane with a pore size of 2μm to 5μm and a thickness of 50μm to 250μm. The blood filtration layer 200 is coated with a fourth reagent, which includes buffer II, protective agent II, and anti-RBC antibody. Buffer II is Tris-HCl buffer with a pH of 7.2 to 7.8 and a concentration of 0.05mol / L to 0.1mol / L. Protective agent II is at least one of trehalose, sucrose, bovine serum albumin, gelatin, and xanthan gum, with a content of 0.1wt% to 0.5wt%. The content of anti-RBC antibody is 0.1mg / mL to 0.5mg / mL. The filtration layer 200 employs a 2μm–5μm large-pore glass fiber membrane combined with coated anti-RBC antibodies to construct an immunofiltration mechanism. The large-pore structure ensures that red blood cells can smoothly enter the membrane and fully contact the antibodies. The anti-RBC antibodies, through specific immunobinding, firmly capture and fix the red blood cells within the three-dimensional mesh structure of the glass fiber membrane. This immunorecognition-based capture method, compared to simple physical filtration, has higher specificity and efficiency, effectively preventing red blood cells from penetrating the filter membrane and thus avoiding interference from colored substances in the underlying optical detection. Traditional physical filtration methods may cause red blood cells to rupture due to mechanical pressure, releasing hemoglobin and causing interference. This invention, through antibody-mediated specific binding, achieves gentle and firm fixation of red blood cells, significantly reducing the risk of hemoglobin leakage due to physical cell rupture. This gentle retention method effectively reduces the possible false color background, improving the specificity and accuracy of the detection. A thickness of 50μm to 250μm ensures that the filtration layer 200 can hold sufficient coating reagents, allowing red blood cells to be effectively retained within it. Too thin a layer may result in insufficient reagent coating, reducing red blood cell retention; too thick a layer may increase blood sample osmotic resistance, affecting detection speed. The pore size (2μm to 5μm) and thickness (50μm to 250μm) of the filtration layer 200 are designed to minimize plasma osmotic resistance while ensuring sufficient antibody coating and red blood cell retention capacity. This allows plasma to quickly and smoothly penetrate the filtration layer 200 into the subsequent reaction zone, while efficiently retaining chromogenic cells in the upper layer. This achieves efficient separation of blood cells and plasma, ensuring the speed and reliability of direct whole blood testing. The addition of Buffer 2 and Protectant 2 provides a stable microenvironment for the anti-RBC antibody in a dry state and during storage, maintaining its biological activity. Combined with the chemical inertness and stable physical structure of the glass fiber membrane itself, this ensures the consistency of the function of the filtration layer 200 throughout the test strip's shelf life. When a whole blood sample diffuses uniformly through diffusion layer 100 to filtration layer 200, the red blood cells in the whole blood sample bind to the anti-RBC antibody in filtration layer 200, causing the colored substance to remain in the upper layer and not interfere with the color development in the lower layer, thus achieving the purpose of testing whole blood.The filtration layer 200 uses a large-pore glass fiber membrane coated with anti-RBC antibodies. While ensuring rapid plasma permeation, the large-pore glass fiber membrane's three-dimensional network structure provides retention space for antibody-erythrocyte complexes. Simultaneously, the anti-RBC antibodies specifically bind to erythrocytes, trapping them in the upper layer of filtration layer 200. This effectively reduces interference from colored substances on the lower layer's colorimetric reaction, enabling direct detection of whole blood samples. The selective removal of colored components via immunobinding, coupled with the specific binding of anti-RBC antibodies to erythrocytes, avoids false colorimetric interference caused by cell rupture or non-specific adsorption that may occur with traditional physical filtration methods. This reduces the risk of false positives or false negatives and significantly improves detection specificity. The anti-RBC antibodies are covalently or electrostatically fixed to the glass fiber membrane. Combined with the membrane's chemical inertness, this ensures the stability of filtration layer 200 during storage, preventing fluctuations in filtration efficiency due to antibody shedding or membrane structure changes. The trapped colored substances are confined to the upper layer of filtration layer 200, preventing them from entering the downstream reaction layer 600 and interfering with detection, thus improving the detection sensitivity for low-concentration samples. When a whole blood sample is evenly diffused through the diffusion layer 100 to the filtration layer 200, the red blood cells in the whole blood sample bind to the anti-RBC antibodies in the filtration layer 200, causing the colored substances to remain in the upper layer and not interfere with the color development in the lower layer, thus achieving the purpose of testing whole blood. The filtration layer 200 uses a large-pore glass fiber membrane coated with anti-RBC antibodies. While ensuring rapid plasma permeation, the large-pore glass fiber membrane's three-dimensional network structure provides retention space for antibody-erythrocyte complexes. Simultaneously, the anti-RBC antibodies specifically bind to erythrocytes, trapping them in the upper layer of filtration layer 200. This effectively reduces interference from colored substances on the lower layer's colorimetric reaction, enabling direct detection of whole blood samples. The selective removal of colored components via immunobinding, coupled with the specific binding of anti-RBC antibodies to erythrocytes, avoids false colorimetric interference caused by cell rupture or non-specific adsorption that may occur with traditional physical filtration methods. This reduces the risk of false positives or false negatives and significantly improves detection specificity. The anti-RBC antibodies are covalently or electrostatically fixed to the glass fiber membrane. Combined with the membrane's chemical inertness, this ensures the stability of filtration layer 200 during storage, preventing fluctuations in filtration efficiency due to antibody shedding or membrane structure changes. The trapped colored substances are confined to the upper layer of filtration layer 200, preventing them from entering the downstream reaction layer 600 and interfering with detection, thus improving the detection sensitivity for low-concentration samples. Tris-HCl buffer (pH 7.2–7.8) simulates the physiological environment, ensuring that anti-RBC antibodies maintain their optimal conformation, resisting the influence of different samples on pH, and extending the shelf life of antibody activity. The anti-RBC antibody concentration (0.1 mg / mL–0.5 mg / mL) ensures saturated binding while avoiding steric hindrance or non-specific adsorption caused by excessive antibody, balancing retention efficiency and cost control.The synergistic effect of the aforementioned parameters allows the filtration layer 200 to retain colored substances while allowing plasma proteins to pass through, eliminating detection biases caused by hemolysis or loss of plasma components in traditional methods, and meeting the clinical needs of direct whole blood testing. By defining the concentration, pH, and type of components, precise control is achieved at the levels of molecular interactions, hydrodynamics, and storage stability. This enables the filtration layer 200 to possess highly efficient colored substance removal, rapid plasma separation, and long-term storage properties, providing a reliable pretreatment guarantee for the dry chemical detection of high-density lipoprotein cholesterol in whole blood. Similarly, by defining the concentration, pH, and type of key components in the filtration layer 200, precise control is achieved at the levels of molecular interactions, hydrodynamics, and storage stability. This enables the filtration layer 200 to possess highly efficient red blood cell removal, rapid plasma separation, and long-term storage properties, providing a reliable pretreatment guarantee for the dry chemical detection of high-density lipoprotein cholesterol in whole blood.

[0041] Optionally, the blood filtration layer is prepared by immersing the material of the blood filtration layer in the prepared fourth reagent for 10-20 seconds and drying it in an oven at 37°C for 30 minutes.

[0042] In this embodiment, the material of the reaction layer 600 is one of cotton, polyethersulfone, and acetate fiber synthetic membrane; the pore size of the reaction layer 600 is 0.2μm to 0.8μm, and the thickness is 50μm to 250μm; the reaction layer 600 is coated with a fifth reagent, which includes buffer solution, substrate, enzyme and protectant, and surfactant. When the sample diffuses into the reaction layer 600, peroxide is generated under the catalysis of the enzyme in the reaction layer 600. The peroxide reacts with the substrate to generate a blue substance for color development. Buffer 3 is HEPES buffer or Tris-HCl buffer, pH 7.2–7.8, concentration 0.05 mol / L–0.1 mol / L; substrate is one of 4-aminoantipyrine or 3-methyl-2-benzothiazolinone hydrazone, content 0.1 wt%–1 wt%; enzyme is one of cholesterol esterase, cholesterol oxidase, or peroxidase, content 0.1 wt%–1 wt% respectively; protectant 3 is at least one of trehalose, sucrose, bovine serum albumin, gelatin, or xanthan gum, content 0.1 wt%–0.5 wt%. The flexibility of cotton fibers ensures a tight fit with the supplementary precipitate layer 500, avoiding edge effects caused by lateral sample diffusion. The rigid framework of polyethersulfone and the hydrophilicity of cotton / acetate fibers synergistically regulate the wettability of the reaction interface, ensuring uniform distribution of the chromogenic reagent and sufficient contact with albumin. The high mechanical strength of polyethersulfone prevents membrane rupture during sample addition or lamination, and its chemical resistance allows it to withstand acidic / alkaline environments for the chromogenic reaction. The hydroxyl active sites of acetate fibers can covalently couple and fix the chromogenic molecules, reducing the migration or inactivation of the reagent layer during storage. The pore size of 0.2μm to 0.8μm ensures that albumin in the sample can pass through smoothly and react with the coating reagent, while effectively intercepting large molecular impurities to avoid interference with the reaction and signal attenuation, thus improving detection sensitivity. The thickness design of 50μm to 250μm provides sufficient space for the coating reagent, ensuring the reaction can proceed fully; on the other hand, it controls the diffusion rate of the sample within the layer, allowing sufficient time for albumin and the coating reagent to contact and react. If the pore size of the reaction layer 600 is too thin, it may lead to incomplete reaction; if it is too thick, it will prolong the detection time and reduce the detection efficiency. Optionally, the pore size of the reaction layer 600 can be set in a gradient, with the upper layer (0.6μm to 0.8μm) intercepting residual cell debris and the lower layer (0.2μm to 0.3μm) enriching the chromogenic products, forming the final filtration barrier to ensure that the reaction layer 600 only receives pre-treated and purified albumin, eliminating interference from whole blood samples on absorbance detection. Optionally, the material of the reaction layer 600 is polyethersulfone and cotton or acetate fiber. The rigid framework of polyethersulfone and the hydrophilicity of cotton / acetate fiber synergistically regulate the wettability of the reaction interface, ensuring that the chromogenic reagent is evenly distributed and in full contact with the analyte.Buffer 3 provides a stable reaction environment for the colorimetric reaction of high-density lipoprotein cholesterol (HDL-C) with enzymes and substrates. The surfactant, through its hydrophilicity, evenly distributes the filtered HDL-C on the membrane, ensuring uniform color development. Protectant 3 effectively inhibits enzyme and substrate degradation, extending their shelf life at room temperature. Combined with the material of reaction layer 600 selected in this invention, it balances the reagent loading capacity of reaction layer 600 without affecting its colorimetric sensitivity, ultimately ensuring a precise correlation between the color intensity and HDL-C concentration, while also guaranteeing the long-term stability of the reagent system. Reaction layer 600, as the final detection module, forms a cascade purification system with the preceding blood filtration layer 200 (removing colored substances), pre-precipitation layer 300, precipitation layer 400, and supplementary precipitation layer 500 (removing non-HDL-C). The final colorimetric signal is only correlated with HDL-C concentration, significantly reducing detection bias in complex samples.

[0043] Optionally, the reaction layer is prepared by immersing the material of the reaction layer in the prepared fifth reagent for 10-20 seconds and drying it in an oven at 37°C for 30 minutes.

[0044] In this embodiment, a base plate 700 is also provided on the lower surface of the reaction layer 600; the dry chemical test paper also includes an upper cover 800 and a lower cover 900. The upper cover 800 has a sample application hole, and the lower cover 900 has a test hole. The upper cover 800 is fastened to the lower cover 900, and the sample application hole and the test hole are arranged vertically correspondingly. By fastening the upper cover 800 and the lower cover 900, the diffusion layer 100, the blood filtration layer 200, the pre-precipitation layer 300, the precipitation layer 400, the supplementary precipitation layer 500, the reaction layer 600, and the base plate 700 are clamped in the cavity enclosed by the upper cover 800 and the lower cover 900, and the diffusion layer 100, the blood filtration layer 200, the pre-precipitation layer 300, the precipitation layer 400, the supplementary precipitation layer 500, and the reaction layer 600 are located in the area corresponding to the sample application hole and the test hole. The viewing window of the base plate 700 is matched with the test hole. The corresponding arrangement of the sample application wells and test wells ensures that whole blood samples vertically penetrate through the diffusion layer 100 to the lower functional membranes (filtration layer 200, pre-precipitation layer 300, precipitation layer 400, supplementary precipitation layer 500, and reaction layer 600), avoiding edge effects or uneven reactions caused by lateral diffusion and improving test repeatability. The viewing window of the base plate 700 matches the test wells to define the optical detection area, eliminating background interference from non-reaction areas and making the colorimetric signal reading more accurate. The clamping structure of the upper cover 800 and lower cover 900 fixes the relative positions of each membrane layer (diffusion layer 100 to reaction layer 600), preventing interlayer displacement, deformation, or separation during transportation or use, and ensuring batch-to-batch consistency. The cavity sealing design reduces the corrosion of test strip reagents by environmental humidity and oxygen, extending the shelf life at room temperature. The upper cover 800 and lower cover 900 interlock to form the cover body. The cover body structure, through the coordinated design of hole guidance, clamping fixation, and sealing protection, simplifies operation while ensuring the functional integrity and detection reliability of the multi-layer test strip. The cap can be made of materials such as polyethylene terephthalate, polystyrene, or polyvinyl chloride, with polyvinyl chloride being the best choice. The cap can be divided into a handheld area and a testing area, with the testing area being the main body of the test strip. In the testing area, the diffusion layer 100, blood filtration layer 200, pre-precipitation layer 300, precipitation layer 400, supplementary precipitation layer 500, and reaction layer 600 are sandwiched between the upper cap 800 and the lower cap 900 in an overlapping manner. The upper cap 800 and the lower cap 900 have circular holes in this area, which are the sample application hole and the testing hole, respectively.

[0045] This embodiment of the testing system for quantitatively determining high-density lipoprotein cholesterol (HDL-C) levels in human whole blood includes the aforementioned dry chemical test strip for quantitative determination of HDL-C levels in human whole blood, and a reflectometer. The dry chemical test strip is inserted into the reflectometer, which controls the reaction temperature at 37±0.5℃ and measures at a wavelength of 630nm. It converts the light signal into HDL-C concentration using a built-in standard curve. In use, the dry chemical test strip is inserted into the reflectometer, which controls the reaction temperature at 37±0.5℃ and measures at a wavelength of 630nm. After the reaction time is reached, the instrument automatically reads the reflected light density and converts the light signal into HDL-C concentration using the built-in standard curve. The test results are automatically reported and stored, and can be printed, projected, displayed on a screen, or viewed online. The plug-and-play design of the test strip avoids the cumbersome manual calibration steps required by traditional testing systems, adapting to the rapid testing needs of primary healthcare settings. The reflectivity detection mode is adapted to the solid-phase colorimetric characteristics of the dry chemical test strip, overcoming the dependence of the transmission method on liquid samples and achieving direct quantification of whole blood samples at the terminal. The temperature control module compensates for potential reaction rate differences caused by room temperature storage of test strips, ensuring consistent results across different batches. The isothermal reaction (37±0.5℃) simulates the human physiological environment, ensuring stable colorimetric reaction kinetics and avoiding detection deviations caused by temperature fluctuations, especially improving accuracy for low-concentration samples. 630nm wavelength detection matches the maximum absorption peak of the bromocresol green / violet colorimetric products, maximizing the signal-to-noise ratio and reducing background interference. The built-in standard curve, through pre-calibration of the reflectance-concentration relationship of different concentrations of high-density lipoprotein cholesterol, directly outputs quantitative results, eliminating subjective errors from manual interpretation. Automatic result reporting and storage standardize the testing process, supporting data traceability and quality control analysis, meeting clinical laboratory accreditation requirements. Functions such as printing, projection, screen sharing, or remote online reading provide instant output of standardized reports, reducing manual transcription errors and improving result traceability. Through standardized instrument parameters, automated testing, and closed-loop adaptation with test strips, the testing system combines the convenience of dry chemistry test strips with the reliability of laboratory-grade quantitative analysis, overcoming the technical bottlenecks of traditional methods in terms of operational complexity, environmental sensitivity, and data management.

[0046] In practice, a dry chemical test strip and testing system for quantitatively determining the content of high-density lipoprotein cholesterol in human whole blood are provided. The system includes, from top to bottom, a top cover 800, a diffusion layer 100, a blood filtration layer 200, a pre-precipitation layer 300, a precipitation layer 400, a supplementary precipitation layer 500, a reaction layer 600, a base plate 700, and a bottom cover 900. The top cover 800 and the bottom cover 900 are respectively provided with a sample application hole and a test hole. A fourth reagent is coated on the blood filtration layer 200. A first reagent, a second reagent, and a third reagent are respectively coated on the pre-precipitation layer 300, the precipitation layer 400, and the supplementary precipitation layer 500. A fifth reagent is coated on the reaction layer 600. The test sample is dropped onto the diffusion layer 100 through the sample well. After the sample diffuses to the reaction layer 600, the high-density lipoprotein cholesterol in the sample reacts with the reagents in the reaction layer 600 to produce a colorimetric reaction. The intensity of the color is directly proportional to the concentration of high-density lipoprotein cholesterol in the sample. By measuring the color on the reaction layer 600 through the test well using a reflectometer, the concentration of high-density lipoprotein cholesterol in the sample can be quantitatively determined. This test strip is used to quantitatively determine the content of high-density lipoprotein cholesterol in human whole blood, providing a basis for disease diagnosis and is suitable for promotion and use in primary healthcare markets.

[0047] Example 1: The upper cover 800 and lower cover 900 are made of polyvinyl chloride (PVC) material, with a thickness of 2 mm, a length of 9 cm, and a width of 20 cm. The upper cover 800 and lower cover 900 have sample loading and test wells respectively, with a well diameter of 4 mm and a well spacing of 15 mm. The diffusion layer has a pore size of 50 μm and a thickness of 100 μm. Preparation of the blood filtration layer: The blood filtration layer is made of glass fiber membrane with a pore size of 2 μm and a thickness of 100 μm. The glass fiber membrane is immersed in the prepared first reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the fourth reagent for the blood filtration layer is as follows: Tris-HCl buffer 0.07 mol / L, pH 7.2; anti-RBC antibody 0.2 mg / mL; trehalose 0.3 wt%.

[0048] Preparation of the pre-precipitated layer: The pre-precipitated layer was made of glass cellulose membrane with a pore size of 0.5 μm and a thickness of 100 μm. The glass cellulose membrane was immersed in the prepared first reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the first reagent for the pre-precipitated layer was as follows: Tris-HCl buffer 0.07 mol / L, pH 7.2; phosphotungstic acid 1 wt%; magnesium chloride 0.5 wt%; bovine serum albumin 0.5 wt%.

[0049] Preparation of the precipitate layer: The precipitate layer is made of polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared second reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the second reagent for the precipitate layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; dextran sulfate (molecular weight 40000) 1 wt%; magnesium chloride 1 wt%; bovine serum albumin 0.5%.

[0050] Preparation of the supplementary precipitate layer: The supplementary precipitate layer is made of polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared third reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the third reagent for the supplementary precipitate layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; polyethyleneimine 1 wt%; bovine serum albumin 0.5%.

[0051] Preparation of the reaction layer: The reaction layer is a polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared fifth reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the fifth reagent for the reaction layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; 4-aminoantipyrine 0.5 wt%; MAOS (N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethylaniline sodium salt monohydrate) 0.1 wt%; cholesterol esterase 0.2 wt%; cholesterol oxidase 0.1 wt%; peroxidase 0.1 wt%; trehalose 0.1 wt%; xanthan gum 0.5 wt%.

[0052] Different concentrations of high-density lipoprotein cholesterol samples were tested. 5 μL of sample was added to the sample well, and the result was measured using a reflectometer for 200 seconds. The test results are shown in the table below:

[0053] Test results show that the detection system upon which the test strip in this embodiment is based exhibits good performance. Specifically, there is a positive correlation between the high-density lipoprotein cholesterol concentration and the characteristic value obtained by the test strip using a reflectometer. Within the set concentration range, i.e., as the high-density lipoprotein cholesterol concentration gradually increases from 0.5 mmol / L to 2.5 mmol / L, the corresponding characteristic value monotonically and continuously rises from 4512 to 12753. This trend indicates that the detection system has good concentration response characteristics in the range of 0.5 mmol / L - 2.5 mmol / L.

[0054] Example 2: The upper cover 800 and lower cover 900 are made of polyvinyl chloride (PVC) material, with a thickness of 2 mm, a length of 9 cm, and a width of 20 cm. The upper cover 800 and lower cover 900 have sample loading holes and test holes respectively, with a hole diameter of 4 mm and a hole spacing of 15 mm. The diffusion layer has a pore size of 50 μm and a thickness of 100 μm.

[0055] Preparation of the filtration layer: The filtration layer is made of glass fiber membrane with a pore size of 2 μm and a thickness of 100 μm. The glass fiber membrane is immersed in the prepared fourth reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the fourth reagent for the filtration layer is as follows: Tris-HCl buffer 0.07 mol / L, pH 7.2; anti-RBC antibody 0.2 mg / mL; trehalose 0.3 wt%.

[0056] Preparation of the pre-precipitated layer: The pre-precipitated layer was made of glass cellulose membrane with a pore size of 0.5 μm and a thickness of 100 μm. The glass cellulose membrane was immersed in the prepared first reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the first reagent for the pre-precipitated layer was as follows: Tris-HCl buffer 0.07 mol / L, pH 7.2; dextran sulfate (molecular weight 500,000) 1 wt%; magnesium chloride 1 wt%; bovine serum albumin 0.5 wt%.

[0057] Preparation of the precipitate layer: The precipitate layer is made of polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared second reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the second reagent for the precipitate layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; dextran sulfate (molecular weight 40000) 1 wt%; magnesium chloride 1 wt%; bovine serum albumin 0.5%.

[0058] Preparation of the supplementary precipitate layer: The supplementary precipitate layer is made of polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared third reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the third reagent for the supplementary precipitate layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; polyethyleneimine 1 wt%; bovine serum albumin 0.5%.

[0059] Preparation of the reaction layer: The reaction layer is a polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared fifth reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the fifth reagent for the reaction layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; 4-aminoantipyrine 0.5 wt%; MAOS (N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethylaniline sodium salt monohydrate) 0.1 wt%; cholesterol esterase 0.2 wt%; cholesterol oxidase 0.1 wt%; peroxidase 0.1 wt%; trehalose 0.1 wt%; xanthan gum 0.5 wt%.

[0060] Different concentrations of high-density lipoprotein cholesterol samples were tested. 5 μL of sample was added to the sample well, and the result was measured using a reflectometer for 200 seconds. The test results are shown in the table below:

[0061] Test results show that the detection system upon which the test strip in this embodiment is based exhibits excellent performance. Specifically, there is a significant positive correlation between the high-density lipoprotein cholesterol concentration and the characteristic value obtained by the test strip using a reflectometer. Within the set concentration range, i.e., as the high-density lipoprotein cholesterol concentration gradually increases from 0.5 mmol / L to 2.5 mmol / L, the corresponding characteristic value monotonically and continuously rises from 4134 to 13556. This trend indicates that the detection system possesses excellent concentration response characteristics within the range of 0.5 mmol / L to 2.5 mmol / L.

[0062] Furthermore, this test strip demonstrates excellent detection efficiency, completing the determination of high-density lipoprotein cholesterol (HDL-C) levels in whole blood in just 200 seconds. Simultaneously, the strict positive correlation and monotonically increasing relationship between concentration and characteristic values ​​further proves that the test strip can accurately quantify HDL-C concentration, fully validating the reliability of this dry chemical test strip for the quantitative detection of HDL-C levels in whole blood.

[0063] Compared to Example 1, both precipitant one and precipitant two in this embodiment include dextran sulfate, wherein the molecular weight of the dextran sulfate used in precipitant one is greater than that used in precipitant two. Within the set concentration range for testing, i.e., when the high-density lipoprotein cholesterol concentration gradually increases from 0.5 mmol / L to 2.5 mmol / L, Example 1 exhibits relatively poor linearity of characteristic values ​​at high concentration levels (2.0 mmol / L-2.5 mmol / L), and the excessive deviation adversely affects the setpoint control. In contrast, this embodiment demonstrates superior concentration response characteristics.

[0064] Example 3: The upper cover 800 and lower cover 900 are made of polyvinyl chloride (PVC) material, with a thickness of 2 mm, a length of 9 cm, and a width of 20 cm. The upper cover 800 and lower cover 900 have sample loading holes and test holes respectively, with a hole diameter of 4 mm and a hole spacing of 15 mm. The diffusion layer has a pore size of 50 μm and a thickness of 100 μm.

[0065] Preparation of the filtration layer: The filtration layer is made of glass fiber membrane with a pore size of 2 μm and a thickness of 100 μm. The glass fiber membrane is immersed in the prepared fourth reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the fourth reagent for the filtration layer is as follows: Tris-HCl buffer 0.07 mol / L, pH 7.2; anti-RBC antibody 0.2 mg / mL; trehalose 0.3 wt%.

[0066] Preparation of the pre-precipitated layer: The pre-precipitated layer was made of glass cellulose membrane with a pore size of 0.5 μm and a thickness of 100 μm. The glass cellulose membrane was immersed in the prepared first reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the first reagent for the pre-precipitated layer was as follows: Tris-HCl buffer 0.07 mol / L, pH 7.2; dextran sulfate (molecular weight 200,000) 1 wt%; magnesium chloride 1 wt%; bovine serum albumin 0.5 wt%.

[0067] Preparation of the precipitate layer: The precipitate layer is made of polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared second reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the second reagent for the precipitate layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; dextran sulfate (molecular weight 40000) 1 wt%; magnesium chloride 1 wt%; bovine serum albumin 0.5%.

[0068] Preparation of the supplementary precipitate layer: The supplementary precipitate layer is made of polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared third reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the third reagent for the supplementary precipitate layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; polyethyleneimine 1 wt%; bovine serum albumin 0.5%.

[0069] Preparation of the reaction layer: The reaction layer is a polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared fifth reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the fifth reagent for the reaction layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; 4-aminoantipyrine 0.5 wt%; MAOS (N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethylaniline sodium salt monohydrate) 0.1 wt%; cholesterol esterase 0.2 wt%; cholesterol oxidase 0.1 wt%; peroxidase 0.1 wt%; trehalose 0.1 wt%; xanthan gum 0.5 wt%.

[0070] Different concentrations of high-density lipoprotein cholesterol samples were tested. 5 μL of sample was added to the sample well, and the result was measured using a reflectometer for 200 seconds. The test results are shown in the table below:

[0071] Compared to Example 2, this example differs in the precipitant configuration, specifically in the molecular weight of the dextran sulfate in precipitant one and precipitant two. In Example 2, the dextran sulfate used in precipitant one had a molecular weight of 500,000, while that used in precipitant two had a molecular weight of 40,000; however, in this example, the molecular weight of the dextran sulfate in precipitant one is adjusted to 200,000, while that in precipitant two remains at 40,000.

[0072] Test results show that within the set concentration range, i.e., as the high-density lipoprotein cholesterol concentration gradually increases from 0.5 mmol / L to 2.5 mmol / L, the characteristic values ​​in this embodiment exhibit a certain pattern of change, but the linear range is narrow. This phenomenon indicates that within the set concentration range, the detection system in this embodiment is less effective at precipitating non-high-density lipoproteins (non-HDL) than in Example 2, failing to achieve complete precipitation of non-HDL. Consequently, the test results directly reflect a portion of the total cholesterol value.

[0073] Example 4: The upper cover 800 and lower cover 900 are made of polyvinyl chloride (PVC) material, with a thickness of 2 mm, a length of 9 cm, and a width of 20 cm. The upper cover 800 and lower cover 900 have sample loading holes and test holes respectively, with a hole diameter of 4 mm and a hole spacing of 15 mm. The diffusion layer has a pore size of 50 μm and a thickness of 100 μm.

[0074] Preparation of the filtration layer: The filtration layer is made of glass fiber membrane with a pore size of 2 μm and a thickness of 100 μm. The glass fiber membrane is immersed in the prepared fourth reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the fourth reagent for the filtration layer is as follows: Tris-HCl buffer 0.07 mol / L, pH 7.2; anti-RBC antibody 0.2 mg / mL; trehalose 0.3 wt%.

[0075] Preparation of the pre-precipitated layer: The pre-precipitated layer was made of glass cellulose membrane with a pore size of 0.5 μm and a thickness of 100 μm. The glass cellulose membrane was immersed in the prepared first reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the first reagent for the pre-precipitated layer was as follows: Tris-HCl buffer 0.07 mol / L, pH 7.2; dextran sulfate (molecular weight 500,000) 1 wt%; magnesium chloride 2 wt%; bovine serum albumin 0.5 wt%.

[0076] Preparation of the precipitate layer: The precipitate layer was made of polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane was immersed in the prepared second reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the second reagent for the precipitate layer was as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; dextran sulfate (molecular weight 40000) 1 wt%; magnesium chloride 2 wt%; bovine serum albumin 0.5%.

[0077] Preparation of the supplementary precipitate layer: The supplementary precipitate layer is made of polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared third reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the third reagent for the supplementary precipitate layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; polyethyleneimine 1 wt%; bovine serum albumin 0.5%.

[0078] Preparation of the reaction layer: The reaction layer is a polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared fifth reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the fifth reagent for the reaction layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; 4-aminoantipyrine 0.5 wt%; MAOS (N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethylaniline sodium salt monohydrate) 0.1 wt%; cholesterol esterase 0.2 wt%; cholesterol oxidase 0.1 wt%; peroxidase 0.1 wt%; trehalose 0.1 wt%; xanthan gum 0.5 wt%.

[0079] Different concentrations of high-density lipoprotein cholesterol samples were tested. 5 μL of sample was added to the sample well, and the result was measured using a reflectometer for 200 seconds. The test results are shown in the table below:

[0080] In this embodiment, by replacing the amount of magnesium ions in the pre-precipitated layer and the precipitated layer in Example 2 with 2wt%, within the set concentration range for testing, i.e., as the high-density lipoprotein cholesterol concentration gradually increases from 0.5 mmol / L to 2.5 mmol / L, the corresponding characteristic values ​​show a significant positive correlation. This phenomenon indicates that within the set concentration range for testing, the detection system of this embodiment has achieved relatively complete precipitation of non-high-density lipoproteins (non-HDL).

[0081] Example 5: The upper cover 800 and lower cover 900 are made of polyvinyl chloride (PVC) material, with a thickness of 2 mm, a length of 9 cm, and a width of 20 cm. The upper cover 800 and lower cover 900 have sample loading holes and test holes respectively, with a hole diameter of 4 mm and a hole spacing of 15 mm. The diffusion layer has a pore size of 50 μm and a thickness of 100 μm.

[0082] Preparation of the filtration layer: The filtration layer is made of glass fiber membrane with a pore size of 2 μm and a thickness of 100 μm. The glass fiber membrane is immersed in the prepared fourth reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the fourth reagent for the filtration layer is as follows: Tris-HCl buffer 0.07 mol / L, pH 7.2; anti-RBC antibody 0.2 mg / mL; trehalose 0.3 wt%.

[0083] Preparation of the pre-precipitation layer: The pre-precipitation layer was made of glass cellulose membrane with a pore size of 0.5 μm and a thickness of 100 μm. The glass cellulose membrane was immersed in the prepared first reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the first reagent for the pre-precipitation layer was as follows: Tris-HCl buffer 0.07 mol / L, pH 7.2; dextran sulfate (molecular weight 500,000) 1 wt%; magnesium chloride 3 wt%; bovine serum albumin 0.5 wt%.

[0084] Preparation of the precipitate layer: The precipitate layer is made of polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared second reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the second reagent for the precipitate layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; dextran sulfate (molecular weight 40000) 1 wt%; magnesium chloride 3 wt%; bovine serum albumin 0.5%.

[0085] Preparation of the supplementary precipitate layer: The supplementary precipitate layer is made of polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared third reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the third reagent for the supplementary precipitate layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; polyethyleneimine 1 wt%; bovine serum albumin 0.5%.

[0086] Preparation of the reaction layer: The reaction layer is a polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared fifth reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the fifth reagent for the reaction layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; 4-aminoantipyrine 0.5 wt%; MAOS (N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethylaniline sodium salt monohydrate) 0.1 wt%; cholesterol esterase 0.2 wt%; cholesterol oxidase 0.1 wt%; peroxidase 0.1 wt%; trehalose 0.1 wt%; xanthan gum 0.5 wt%.

[0087] Different concentrations of high-density lipoprotein cholesterol samples were tested. 5 μL of sample was added to the sample well, and the result was measured using a reflectometer for 200 seconds. The test results are shown in the table below:

[0088] In this embodiment, by replacing the amount of magnesium ions in the pre-precipitated layer and the precipitated layer of Example 2 with 3wt%, within the set concentration range for testing, i.e., as the high-density lipoprotein cholesterol concentration gradually increases from 0.5 mmol / L to 2.5 mmol / L, the corresponding characteristic values ​​show a significant positive correlation. This phenomenon indicates that, within the set concentration range for testing, the detection system of this embodiment has achieved relatively complete precipitation of non-high-density lipoproteins (non-HDL).

[0089] Comparative Example 1: The upper cover 800 and lower cover 900 are made of polyvinyl chloride (PVC) material, with a thickness of 2 mm, a length of 9 cm, and a width of 20 cm. The upper cover 800 and lower cover 900 have sample loading holes and test holes respectively, with a hole diameter of 4 mm and a hole spacing of 15 mm. The diffusion layer has a pore size of 50 μm and a thickness of 100 μm.

[0090] Preparation of the filtration layer: The filtration layer is made of glass fiber membrane with a pore size of 2 μm and a thickness of 100 μm. The glass fiber membrane is immersed in the prepared fourth reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the fourth reagent for the filtration layer is as follows: Tris-HCl buffer 0.07 mol / L, pH 7.2; anti-RBC antibody 0.2 mg / mL; trehalose 0.3 wt%.

[0091] Preparation of the precipitate layer: The precipitate layer is made of polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared second reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the second reagent for the precipitate layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; dextran sulfate (molecular weight 40000) 1 wt%; magnesium chloride 1 wt%; bovine serum albumin 0.5%.

[0092] Preparation of the reaction layer: The reaction layer is a polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared fifth reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the fifth reagent for the reaction layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; 4-aminoantipyrine 0.5 wt%; MAOS (N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethylaniline sodium salt monohydrate) 0.1 wt%; cholesterol esterase 0.2 wt%; cholesterol oxidase 0.1 wt%; peroxidase 0.1 wt%; trehalose 0.1 wt%; xanthan gum 0.5 wt%.

[0093] Different concentrations of high-density lipoprotein cholesterol samples were tested. 5 μL of sample was added to the sample well, and the result was measured using a reflectometer for 200 seconds. The test results are shown in the table below:

[0094] This comparative example only has one layer of precipitation structure. Within the concentration range set in the test, that is, when the high-density lipoprotein cholesterol concentration gradually increases from 0.5 mmol / L to 2.5 mmol / L, the corresponding characteristic value change trend indicates that the detection system failed to completely precipitate non-high-density lipoprotein (non-HDL), thus resulting in a narrower linear range.

[0095] Comparative Example 2: The upper cover 800 and lower cover 900 are made of polyvinyl chloride (PVC) material, with a thickness of 2 mm, a length of 9 cm, and a width of 20 cm. The upper cover 800 and lower cover 900 have sample loading holes and test holes respectively, with a hole diameter of 4 mm and a hole spacing of 15 mm. The diffusion layer has a pore size of 50 μm and a thickness of 100 μm.

[0096] Preparation of the filtration layer: The filtration layer is made of glass fiber membrane with a pore size of 2 μm and a thickness of 100 μm. The glass fiber membrane is immersed in the prepared fourth reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the fourth reagent for the filtration layer is as follows: Tris-HCl buffer 0.07 mol / L, pH 7.2; anti-RBC antibody 0.2 mg / mL; trehalose 0.3 wt%.

[0097] Preparation of the pre-precipitated layer: The pre-precipitated layer was made of glass cellulose membrane with a pore size of 0.5 μm and a thickness of 100 μm. The glass cellulose membrane was immersed in the prepared first reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the first reagent for the pre-precipitated layer was as follows: Tris-HCl buffer 0.07 mol / L, pH 7.2; dextran sulfate (molecular weight 40000) 1 wt%; magnesium chloride 1 wt%; bovine serum albumin 0.5 wt%.

[0098] Preparation of the precipitate layer: The precipitate layer is made of polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared second reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the second reagent for the precipitate layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; dextran sulfate (molecular weight 500,000) 1 wt%; magnesium chloride 1 wt%; bovine serum albumin 0.5%.

[0099] Preparation of the supplementary precipitate layer: The supplementary precipitate layer is made of polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared third reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the third reagent for the supplementary precipitate layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; polyethyleneimine 1 wt%; bovine serum albumin 0.5%.

[0100] Preparation of the reaction layer: The reaction layer is a polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared fifth reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the fifth reagent for the reaction layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; 4-aminoantipyrine 0.5 wt%; MAOS (N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethylaniline sodium salt monohydrate) 0.1 wt%; cholesterol esterase 0.2 wt%; cholesterol oxidase 0.1 wt%; peroxidase 0.1 wt%; trehalose 0.1 wt%; xanthan gum 0.5 wt%.

[0101] Different concentrations of high-density lipoprotein cholesterol samples were tested. 5 μL of sample was added to the sample well, and the result was measured using a reflectometer for 200 seconds. The test results are shown in the table below:

[0102] In this comparative example, the precipitant combination of the pre-precipitation layer and the precipitation layer in Example 2 was adjusted so that the molecular weight of the dextran sulfate used in precipitant one in the pre-precipitation layer was smaller than that of the dextran sulfate used in precipitant two in the precipitation layer. Within the set concentration range for testing, i.e., as the high-density lipoprotein cholesterol concentration gradually increased from 0.5 mmol / L to 2.5 mmol / L, the corresponding characteristic value was very low. The reason for this phenomenon may be that the excessively large dextran sulfate blocked the pores of the polysulfone membrane material in the precipitation layer, preventing the sample from penetrating into the reaction layer.

[0103] Comparative Example 3: The upper cover 800 and lower cover 900 are made of polyvinyl chloride (PVC) material, with a thickness of 2 mm, a length of 9 cm, and a width of 20 cm. The upper cover 800 and lower cover 900 have sample loading holes and test holes respectively, with a hole diameter of 4 mm and a hole spacing of 15 mm. The diffusion layer has a pore size of 50 μm and a thickness of 100 μm.

[0104] Preparation of the filtration layer: The filtration layer is made of glass fiber membrane with a pore size of 2 μm and a thickness of 100 μm. The glass fiber membrane is immersed in the prepared fourth reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the fourth reagent for the filtration layer is as follows: Tris-HCl buffer 0.07 mol / L, pH 7.2; anti-RBC antibody 0.2 mg / mL; trehalose 0.3 wt%.

[0105] Preparation of the pre-precipitated layer: The pre-precipitated layer was made of glass cellulose membrane with a pore size of 0.5 μm and a thickness of 100 μm. The glass cellulose membrane was immersed in the prepared first reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the first reagent for the pre-precipitated layer was as follows: Tris-HCl buffer 0.07 mol / L, pH 7.2; dextran sulfate (molecular weight 500,000) 1 wt%; magnesium chloride 0.5 wt%; bovine serum albumin 0.5 wt%.

[0106] Preparation of the precipitate layer: The precipitate layer was made of polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane was immersed in the prepared second reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the second reagent for the precipitate layer was as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; dextran sulfate (molecular weight 40000) 1 wt%; magnesium chloride 0.5 wt%; bovine serum albumin 0.5%.

[0107] Preparation of the supplementary precipitate layer: The supplementary precipitate layer is made of polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared third reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the third reagent for the supplementary precipitate layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; polyethyleneimine 1 wt%; bovine serum albumin 0.5%.

[0108] Preparation of the reaction layer: The reaction layer is a polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared fifth reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the fifth reagent for the reaction layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; 4-aminoantipyrine 0.5 wt%; MAOS (N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethylaniline sodium salt monohydrate) 0.1 wt%; cholesterol esterase 0.2 wt%; cholesterol oxidase 0.1 wt%; peroxidase 0.1 wt%; trehalose 0.1 wt%; xanthan gum 0.5 wt%.

[0109] Different concentrations of high-density lipoprotein cholesterol samples were tested. 5 μL of sample was added to the sample well, and the result was measured using a reflectometer for 200 seconds. The test results are shown in the table below:

[0110] This comparative example, by replacing the amount of magnesium ions in the pre-precipitated layer and the precipitated layer in Example 2 with 0.5 wt%, shows that the characteristic value change trend within the set concentration range, i.e., when the high-density lipoprotein cholesterol concentration gradually increases from 0.5 mmol / L to 2.5 mmol / L, indicates that the detection system does not completely precipitate non-HDL in the range of 0.5 mmol / L - 2.5 mmol / L.

[0111] Comparative Example 4: The upper cover 800 and lower cover 900 are made of polyvinyl chloride (PVC) material, with a thickness of 2 mm, a length of 9 cm, and a width of 20 cm. The upper cover 800 and lower cover 900 have sample loading holes and test holes respectively, with a hole diameter of 4 mm and a hole spacing of 15 mm. The diffusion layer has a pore size of 50 μm and a thickness of 100 μm.

[0112] Preparation of the filtration layer: The filtration layer is made of glass fiber membrane with a pore size of 2 μm and a thickness of 100 μm. The glass fiber membrane is immersed in the prepared fourth reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the fourth reagent for the filtration layer is as follows: Tris-HCl buffer 0.07 mol / L, pH 7.2; anti-RBC antibody 0.2 mg / mL; trehalose 0.3 wt%.

[0113] Preparation of the pre-precipitated layer: The pre-precipitated layer was made of glass cellulose membrane with a pore size of 0.5 μm and a thickness of 100 μm. The glass cellulose membrane was immersed in the prepared first reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the first reagent for the pre-precipitated layer was as follows: Tris-HCl buffer 0.07 mol / L, pH 7.2; dextran sulfate (molecular weight 500,000) 1 wt%; magnesium chloride 5 wt%; bovine serum albumin 0.5 wt%.

[0114] Preparation of the precipitate layer: The precipitate layer was made of polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane was immersed in the prepared second reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the second reagent for the precipitate layer was as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; dextran sulfate (molecular weight 40000) 1 wt%; magnesium chloride 5 wt%; bovine serum albumin 0.5%.

[0115] Preparation of the supplementary precipitate layer: The supplementary precipitate layer is made of polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared third reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the third reagent for the supplementary precipitate layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; polyethyleneimine 1 wt%; bovine serum albumin 0.5%.

[0116] Preparation of the reaction layer: The reaction layer is a polysulfone membrane with a pore size of 0.5 μm and a thickness of 100 μm. The polysulfone membrane is immersed in the prepared fifth reagent for 1 minute and dried in an oven at 37°C for 30 minutes. The formulation of the fifth reagent for the reaction layer is as follows: Tris-HCl buffer 0.1 mol / L, pH 7.2; 4-aminoantipyrine 0.5 wt%; MAOS (N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethylaniline sodium salt monohydrate) 0.1 wt%; cholesterol esterase 0.2 wt%; cholesterol oxidase 0.1 wt%; peroxidase 0.1 wt%; trehalose 0.1 wt%; xanthan gum 0.5 wt%.

[0117] Different concentrations of high-density lipoprotein cholesterol samples were tested. 5 μL of sample was added to the sample well, and the result was measured using a reflectometer for 200 seconds. The test results are shown in the table below:

[0118] In this comparative example, by replacing the amount of magnesium ions in the pre-precipitated layer and the precipitated layer in Example 2 with 5 wt%, within the set concentration range for testing, i.e., when the high-density lipoprotein cholesterol concentration gradually increased from 0.5 mmol / L to 2.5 mmol / L, the corresponding characteristic values ​​showed no trend and blood leakage occurred. The reason for this phenomenon may be that the addition of excessive cations will affect the filtration capacity of the test strip.

[0119] Matters not covered in this invention are common knowledge.

[0120] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0121] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

[0122] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A dry chemical test strip for quantitatively determining the content of high-density lipoprotein cholesterol in human whole blood, characterized in that, It includes a diffusion layer (100), a blood filtration layer (200), a pre-precipitation layer (300), a precipitation layer (400), a supplementary precipitation layer (500), and a reaction layer (600) arranged in layers from top to bottom. The pre-precipitation layer (300) is coated with a first reagent containing precipitant one; the precipitation layer (400) is coated with a second reagent containing precipitant two; and the supplementary precipitation layer (500) is coated with a third reagent containing precipitant three. Precipitant 1, Precipitant 2 and Precipitant 3 are each selected from at least one of dextran sulfate, polyethylene glycol 2000, phosphotungstic acid and polyethyleneimine, and precipitant 1, precipitant 2 and precipitant 3 are formulated with different formulations; Both precipitant one and precipitant two contain dextran sulfate, wherein the molecular weight of the dextran sulfate used in precipitant one is greater than that used in precipitant two; precipitant three is one of polyethylene glycol 2000 and polyethyleneimine; the content of precipitant one in the first reagent, the content of precipitant two in the second reagent, and the content of precipitant three in the third reagent are all 0.1wt% to 1wt%. Magnesium salts are also added to precipitant one and precipitant two. The magnesium salts are magnesium chloride or magnesium sulfate. The mass ratio of sulfated dextran to magnesium salt is 1:4 to 1:

1.

2. The dry chemical test strip for quantitative determination of high-density lipoprotein cholesterol content in human whole blood according to claim 1, characterized in that, The sulfated dextran in precipitant one is 500,000 sulfated dextran.

3. The dry chemical test strip for quantitative determination of high-density lipoprotein cholesterol content in human whole blood according to claim 1, characterized in that, The sulfated dextran in precipitant two is sulfated dextran 40000.

4. The dry chemical test strip for quantitative determination of high-density lipoprotein cholesterol content in human whole blood according to claim 1, characterized in that, The first, second, and third reagents also contain buffer solution one and protectant one; Buffer 1 is HEPES buffer or Tris-HCl buffer, with a pH of 7.2 to 7.8 and a concentration of 0.05 mol / L to 0.1 mol / L; The protective agent is at least one of trehalose, sucrose, bovine serum albumin, gelatin, and xanthan gum, with a content of 0.1wt% to 0.5wt%.

5. The dry chemical test strip for quantitative determination of high-density lipoprotein cholesterol content in human whole blood according to any one of claims 1 to 4, characterized in that, The material of the filtration layer (200) is a glass fiber membrane with a pore size of 2μm to 5μm and a thickness of 50μm to 250μm. The filtration layer (200) is coated with a fourth reagent, which includes buffer II, protective agent II and anti-RBC antibody. Buffer II is Tris-HCl buffer with a pH of 7.2 to 7.8 and a concentration of 0.05mol / L to 0.1mol / L. Protective agent II is at least one of trehalose, sucrose, bovine serum albumin, gelatin and xanthan gum, with a content of 0.1wt% to 0.5wt%. The content of anti-RBC antibody is 0.1mg / mL to 0.5mg / mL.

6. The dry chemical test strip for quantitative determination of high-density lipoprotein cholesterol content in human whole blood according to any one of claims 1 to 4, characterized in that, The material of the reaction layer (600) is one of cotton, polyethersulfone and acetate fiber synthetic membrane; the pore size of the reaction layer (600) is 0.2μm to 0.8μm and the thickness is 50μm to 250μm; the reaction layer (600) is coated with a fifth reagent, which includes buffer three, substrate, enzyme and protective agent three, and surfactant; buffer three is HEPES buffer or Tris-HCl buffer, pH is 7.2 to 7.8, and concentration is 0.05mol / L to 0.1mol / L; the substrate is one of 4-aminoantipyrine and 3-methyl-2-benzothiazolinone hydrazone, with a content of 0.1wt% to 1wt%; the enzyme is one of cholesterol esterase, cholesterol oxidase and peroxidase, with a content of 0.1wt% to 1wt% respectively; the protective agent three is at least one of trehalose, sucrose, bovine serum albumin, gelatin and xanthan gum, with a content of 0.1wt% to 0.5wt%.

7. The dry chemical test strip for quantitative determination of high-density lipoprotein cholesterol content in human whole blood according to any one of claims 1 to 4, characterized in that, The lower surface of the reaction layer (600) is also provided with a base plate (700); the dry chemical test paper also includes an upper cover (800) and a lower cover (900), the upper cover (800) is provided with a sample application hole, the lower cover (900) is provided with a test hole, the upper cover (800) is fastened to the lower cover (900) and the sample application hole and the test hole are arranged vertically correspondingly; by fastening the upper cover (800) and the lower cover (900), the diffusion layer (100), the blood filtration layer (200), and the pre-precipitation layer (3) are connected. 00), precipitate layer (400), supplementary precipitate layer (500), reaction layer (600) and base plate (700) are sandwiched in the cavity enclosed by upper cover (800) and lower cover (900), and diffusion layer (100), blood filtration layer (200), preprecipitate layer (300), precipitate layer (400), supplementary precipitate layer (500) and reaction layer (600) are located in the area corresponding to the sample application hole and the test hole, and the viewing window of the base plate (700) is matched with the test hole.

8. A testing system for quantitatively determining the content of high-density lipoprotein cholesterol in human whole blood, characterized in that, The dry chemical test strip for quantitative determination of high-density lipoprotein cholesterol content in human whole blood, as described in any one of claims 1 to 7, further includes a reflectometer; the dry chemical test strip is loaded into the reflectometer, which controls the reaction temperature at 37±0.5℃, measures at a wavelength of 630nm, and converts the light signal into high-density lipoprotein cholesterol concentration through a built-in standard curve.

Images