A test strip

Abstract

This application discloses a test strip, including a base plate (1). The base plate (1) is sequentially provided with a sample pad (2), a conjugate pad (3), a reaction membrane (4), and an absorbent pad (5), with adjacent pads in contact with each other. A dissociation pad (6) is also provided, located downstream of the sample pad (2) and upstream of the conjugate pad (3), and in contact with both the sample pad (2) and the conjugate pad (3). The test strip provided by this application can use whole blood samples for detection items requiring dissociation of the target analyte, without the need for pre-sample pretreatment. The detection is convenient, fast, and reliable, making it particularly suitable for POCT testing.

Description

Technical Field

[0001] This application relates to the field of testing equipment technology, and in particular to a testing strip. Background Technology

[0002] Blood components mainly include blood cells, various proteins, water, and ions. Without an anticoagulant, whole blood clots and separates into a blood cell layer and serum. High-speed centrifugation can separate the serum and blood cells. With the addition of an anticoagulant, centrifugation of whole blood can separate blood cells and plasma. Compared to plasma, serum does not contain fibrinogen.

[0003] When performing in vitro diagnostic tests (biochemical and immunoassays), the test sample may be whole blood, serum, or plasma, depending on the specific test and the requirements of the reagents. For some tests, the target analyte needs to be dissociated from the sample. The conventional method is to add a dissociation reagent to the sample buffer and mix the sample and buffer thoroughly to achieve dissociation. However, due to their physicochemical properties (excessive acidity / alkalinity, etc.), dissociation reagents can easily cause hemolysis in whole blood, leading to red blood cell rupture and the release of hemoglobin into the surrounding fluid, affecting the accuracy of the test results. Therefore, for these tests requiring dissociation, it is often only possible to test serum or plasma samples, and whole blood samples cannot be directly tested.

[0004] In testing laboratories, separating serum or plasma from whole blood requires the use of high-speed centrifuges, and the volume of blood centrifuged is in the mL range or higher. Vacuum blood collection tubes are often used for blood collection and centrifugation. For patients, this procedure requires drawing venous blood and waiting for centrifugation, making the entire process time-consuming and cumbersome. Moreover, drawing venous blood from infants and young children is relatively more complex and difficult.

[0005] In the field of POCT (point-of-care testing), there is a preference for testing methods that require no sample pretreatment or have a rapid and simple pretreatment process, and for finger-prick blood sampling to improve testing efficiency and expand applicability. However, currently, for the detection of targets that require dissociation, the aforementioned issues still cannot meet the needs of POCT testing. Utility Model Content

[0006] To solve the above-mentioned technical problems, the purpose of this utility model is to provide a test strip. The test strip provided in this application can also use whole blood samples for detection items that require the dissociation of target substances, and no sample pretreatment is required. The detection is convenient, fast and reliable, and it is especially suitable for POCT detection.

[0007] The technical solution provided by this utility model is as follows:

[0008] A test strip includes a base plate on which a sample pad, a conjugate pad, a reaction membrane, and an absorbent pad are sequentially arranged, with adjacent pads in contact with each other. A dissociation pad is also provided, which is located downstream of the sample pad and upstream of the conjugate pad, and is in contact with the sample pad and the conjugate pad, respectively.

[0009] Preferably, the sample pad overlaps the dissociation pad in whole or in part;

[0010] The dissociation pad partially overlaps the bonding pad.

[0011] Preferably, the bonding pad portion overlaps the reaction membrane, and the absorbent pad portion overlaps the reaction membrane.

[0012] Preferably, when there is a partial overlap, the length of the overlap area is 1-2 mm.

[0013] Preferably, when the sample pad is completely overlapped on the dissociation pad, the length of the sample pad is 10-20 mm and the length of the dissociation pad is 22-26 mm.

[0014] When the sample pad partially overlaps the dissociation pad, the length of the dissociation pad is 5-10 mm.

[0015] Preferably, when the sample pad is completely overlapped on the dissociation pad, the length of the sample pad is 10-20 mm and the length of the dissociation pad is 24-25 mm.

[0016] When the sample pad partially overlaps the dissociation pad, the length of the dissociation pad is 7-9 mm.

[0017] Preferably, the width of the test strip is 3.5-4.2 mm, and the widths of the base plate, sample pad, conjugate pad, reaction membrane, absorbent pad, and dissociation pad are the same.

[0018] Preferably, the thickness of the sample pad, conjugation pad, reaction membrane, absorbent pad, and dissociation pad is independently 0.2-0.5 mm.

[0019] Preferably, the binding pad is coated with a fluorescently labeled antibody against the target detection analyte;

[0020] The reaction membrane is provided with a detection band and a quality control band. The detection band is coated with an antibody against the target analyte, and the quality control band is coated with a quality control antibody.

[0021] To address the problems of existing technologies, this application provides a test strip comprising a base plate on which a sample pad, a conjugate pad, a reaction membrane, and an absorbent pad are sequentially arranged, with adjacent pads in contact with each other. A dissociation pad is also provided, located downstream of the sample pad and upstream of the conjugate pad, and in contact with both the sample pad and the conjugate pad. The test strip provided in this application adds a dissociation pad, and the dissociation reagent is stored separately in the dissociation pad, no longer mixed with the sample buffer. The sample first enters the sample pad to trap red blood cells, then enters the dissociation pad to dissociate the target analyte in the sample. After dissociation, the sample enters the conjugate pad for detection. This process avoids contact between red blood cells and the dissociation reagent, preventing hemolysis caused by red blood cell destruction. Therefore, the test strip provided in this application can use whole blood samples for tests requiring target analyte dissociation without prior sample pretreatment. The detection is convenient, fast, and reliable, making it particularly suitable for POCT (Point of Contact Testing). Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of a test strip in an embodiment of this utility model;

[0024] Figure 2 This is a schematic diagram of another structure of the test strip in an embodiment of this utility model;

[0025] Figure 3 This is a comparison diagram of the linear relationship between the data in Table 1 and Table 2 in the embodiments of this utility model.

[0026] Figure labels: 1-Base plate; 2-Sample pad; 3-Binding pad; 4-Reaction membrane; 41-Detection strip; 42-Quality control strip; 5-Absorbent pad; 6-Dissociation pad. Detailed Implementation

[0027] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly set on the other component; when a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to the other component.

[0029] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" or "several" means two or more, unless otherwise explicitly specified.

[0031] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0032] As shown in the figure, this utility model embodiment provides a test strip, including a base plate 1. The base plate 1 is provided with a sample pad 2, a conjugate pad 3, a reaction membrane 4 and an absorbent pad 5 in sequence, and adjacent pads are in contact with each other. A dissociation pad 6 is also provided. The dissociation pad 6 is located downstream of the sample pad 2 and upstream of the conjugate pad 3, and is in contact with the sample pad 2 and the conjugate pad 3 respectively.

[0033] To address the problems of existing technologies, this application provides a test strip comprising a base plate 1, on which a sample pad 2, a conjugate pad 3, a reaction membrane 4, and an absorbent pad 5 are sequentially arranged, with adjacent pads in contact with each other. A dissociation pad 6 is also provided, located downstream of the sample pad 2 and upstream of the conjugate pad 3, and in contact with both the sample pad 2 and the conjugate pad 3. The test strip provided in this application adds a dissociation pad 6, and the dissociation reagent is stored separately in the dissociation pad 6, no longer mixed with the sample buffer. Thus, the sample first enters the sample pad 2 to trap red blood cells, and then enters the dissociation pad 6 to dissociate the target analyte in the sample. After dissociation, the sample enters the conjugate pad 3 for detection. This process avoids contact between red blood cells and the dissociation reagent, preventing hemolysis caused by red blood cell destruction. Therefore, the test strip provided in this application can use whole blood samples for detection items requiring dissociation of target analytes, without the need for pre-sample pretreatment. The detection is convenient, fast, and reliable, and is particularly suitable for POCT testing.

[0034] The innovation of this application lies in the disassembly and recombination of existing sample pad structures, achieving the desired effect through structural changes rather than modifying reagent components. The innovation of this solution lies in enabling the retention or release of specific components in the sample within different pads, unlike conventional methods that lack a specific order for detection items, through changes in the test strip structure. This allows for the detection of whole blood samples requiring the dissociation of target analytes.

[0035] In this application, the assembly of the base plate 1, sample pad 2, binding pad 3, reaction membrane 4, absorbent pad 5, and dissociation pad 6 can be achieved by conventional adhesive methods in the art. The assembly structure between the sample pad 2, binding pad 3, reaction membrane 4, absorbent pad 5, and base plate 1 can be achieved by referring to conventional methods in the prior art.

[0036] In this application, adjacent gaskets being in contact with each other means that they have closely fitting end faces or overlap each other, thereby allowing liquid to flow between different gaskets. For example, the reaction membrane 4 and its adjacent binding pad 3 and absorbent pad 5 have closely fitting end faces or overlap each other, and other adjacent structures are also configured in this way.

[0037] In this application, the dissociation reagent added to the dissociation pad 6 varies depending on the specific test. For example, the dissociation reagent for detecting 25-OH VD can be perfluorooctanoic acid, guanidine hydrochloride, guanidine isothiocyanate, etc. Furthermore, similar target analytes requiring dissociation include tetraiodothyronine (T4), triiodothyronine (T3), and folic acid. Because the dissociation reagent exists solely in the dissociation pad 6, a sufficient concentration is maintained without causing hemolysis.

[0038] Preferably, the sample pad 2 overlaps entirely or partially on the dissociation pad 6;

[0039] The dissociation pad 6 partially overlaps the bonding pad 3.

[0040] The sample pad 2 is preferably fully or partially overlapped with the dissociation pad 6, while the dissociation pad 6 is partially overlapped with the conjugation pad 3, so as to realize the flow and transfer of the sample fluid.

[0041] Specifically, in the first implementation, the sample pad 2 is completely overlapped with the dissociation pad 6. The operator applies the sample to the sample pad 2 by dripping or other means. Since the dissociation pad 6 is located below the sample pad 2, the sample permeates downwards under the influence of gravity. After the red blood cells are intercepted by the sample pad 2, the remaining substances enter the dissociation pad 6 and dissociate. The dissociated sample then enters the conjugate pad 3 through the part of the dissociation pad 6 that overlaps with the conjugate pad 3, and then reacts and is detected with the reagents in the conjugate pad 3.

[0042] As a second implementation method, the sample pad 2 is partially overlapped on the dissociation pad 6, so that the main bodies of the sample pad 2, the dissociation pad 6, and the conjugation pad 3 are roughly on the same horizontal plane (for example, all placed on the base plate 1). At the same time, the part of the sample pad 2 closer to the dissociation pad 6 overlaps on the dissociation pad 6, and the part of the dissociation pad 6 farther away from the sample pad 2 overlaps on the conjugation pad 3, which can also guide the flow of the sample liquid.

[0043] Preferably, the bonding pad 3 partially overlaps the reaction membrane 4, and the absorbent pad 5 partially overlaps the reaction membrane 4.

[0044] In addition to the fact that the sample pad 2 is fully or partially overlapped with the dissociation pad 6, all the pads provided on the base plate 1 are partially overlapped. That is, the sample pad 2 is fully or partially overlapped with the dissociation pad 6, while the dissociation pad 6 is partially overlapped with the binding pad 3, and the binding pad 3 is partially overlapped with the reaction membrane 4, while the reaction membrane 4 remains flat. The other end is the absorbent pad 5, which is partially overlapped with the reaction membrane.

[0045] Preferably, when there is a partial overlap, the length of the overlap area is 1-2 mm.

[0046] When partial overlap is preferred, the length of the overlap area is 1-2 mm. This can be the length where the release pad 6 is located below the sample pad 2 and overlaps the bonding pad 3; or the length where the sample pad 2 partially overlaps the release pad 6 and the release pad 6 overlaps the bonding pad 3; or the length where other pads directly overlap each other. The overlap lengths between different pads can be the same or different.

[0047] The length direction referred to in this application is from the sample pad 2 to the absorbent pad 5, which is the approximate direction of sample liquid flow.

[0048] Preferably, when the sample pad 2 is fully overlapped on the dissociation pad 6, the length of the sample pad 2 is 10-20 mm and the length of the dissociation pad 6 is 22-26 mm.

[0049] When the sample pad 2 partially overlaps the dissociation pad 6, the length of the dissociation pad 6 is 5-10 mm.

[0050] Preferably, when the sample pad 2 is fully overlapped on the dissociation pad 6, the length of the sample pad 2 is 10-20 mm, and the length of the dissociation pad 6 is 24-25 mm.

[0051] When the sample pad 2 partially overlaps the dissociation pad 6, the length of the dissociation pad 6 is 7-9 mm.

[0052] In this application, the length of the dissociation pad 6 varies depending on whether the sample pad 2 is fully overlapped or partially overlapped. Specifically, when the sample pad 2 is fully overlapped on the dissociation pad 6, the length of the sample pad 2 is 10-20 mm, and the length of the dissociation pad 6 is 22-26 mm, more preferably 24-25 mm. When the sample pad 2 is partially overlapped on the dissociation pad 6, the length of the dissociation pad 6 is 5-10 mm, more preferably 7-9 mm.

[0053] The applicant confirmed through experimental research that the detection repeatability is better when the length of the dissociation pad 6 is within this range.

[0054] Preferably, the width of the test strip is 3.5-4.2 mm, and the widths of the base plate 1, sample pad 2, conjugate pad 3, reaction membrane 4, absorbent pad 5, and dissociation pad 6 are the same.

[0055] The width of the preferred test strip is 3.5-4.2mm, and the widths of the base plate 1, sample pad 2, binding pad 3, reaction membrane 4, absorbent pad 5, and dissociation pad 6 are the same. Then the entire test strip can be obtained by first assembling large-sized materials and then directly cutting them.

[0056] Preferably, the thickness of the sample pad 2, the binding pad 3, the reaction membrane 4, the absorbent pad 5, and the dissociation pad 6 is independently 0.2-0.5 mm.

[0057] Preferably, the thickness of sample pad 2, binding pad 3, reaction membrane 4, absorbent pad 5, and dissociation pad 6 is 0.2-0.5 mm, and the thickness of each structure can be the same or different.

[0058] Preferably, the conjugate pad 3 is coated with a fluorescently labeled antibody against the target detection substance;

[0059] The reaction membrane 4 is provided with a detection band 41 and a control band 42. The detection band 41 is coated with an antibody against the target analyte; the control band 42 is coated with a control antibody.

[0060] The binding pad 3 of this application includes a detection band 41 and a control band 42, which are coated with fluorescently labeled antibodies against the target analyte. The detection band 41 is coated with antibodies against the target analyte, and the control band 42 is coated with a quality control antibody (such as chicken IgY / DNP-BSA).

[0061] The detection band 41 and the quality control band 42 are preferably arranged in parallel (and both are perpendicular to the length direction of the test strip, i.e., perpendicular to the flow direction of the sample), and the distance between them is preferably 4-6 mm.

[0062] Depending on the target object being tested, this application may employ a corresponding binding pad from the prior art.

[0063] In this application, the retention of blood cells can be achieved by methods known in the art. For example, sample pad 2 may contain anti-RBC antibodies to agglutinate red blood cells in whole blood cells. The sample continues to seep into dissociation pad 6, where the dissociation reagent in dissociation pad 6 separates the target substance from the protein in the sample pad. The target substance then binds to the marker on conjugation pad 3 and flows to detection band 41 and control band 42.

[0064] The reaction membrane 4 used in this application is a nitrocellulose membrane. More preferably, the reaction membrane 4 has a thickness of 0.3-0.5 cm and a width of 0.2-0.4 mm. Models such as CN140, CN95, Pall 90, and Millipore 135 can be used.

[0065] More preferably, the reaction membrane 4 further includes a first fiber membrane layer and a second fiber membrane layer, the second fiber membrane layer being adhered to the PVC backing, the first fiber membrane layer being adhered to the second fiber membrane layer, and the detection strip and the quality control strip being disposed on the first fiber membrane layer.

[0066] Example 1

[0067] A test strip includes a base plate 1, on which a sample pad 2, a conjugation pad 3, a reaction membrane 4, and an absorbent pad 5 are sequentially arranged. A dissociation pad 6 is also provided, located downstream of the sample pad 2 and upstream of the conjugation pad 3. The sample pad 2 partially overlaps the dissociation pad 6, the dissociation pad 6 partially overlaps the conjugation pad 3, the conjugation pad 3 partially overlaps the reaction membrane 4, and the absorbent pad 5 partially overlaps the reaction membrane 4. The length of the overlap area between adjacent pads is 1 mm.

[0068] The sample pad 2, conjugate pad 3, reaction membrane 4, absorbent pad 5, and dissociation pad 6 have the same width of 3.8 mm and a thickness of 0.4 mm. The dissociation pad 6 has a length of 8 mm, the sample pad 2 has a length of 18 mm, the conjugate pad 3 has a length of 8 mm, the reaction membrane 4 has a length of 25 mm, and the absorbent pad 5 has a length of 26 mm.

[0069] The binding pad 3 is coated with fluorescently labeled antibodies against the target analyte; the reaction membrane 4 has a detection band 41 and a control band 42, the detection band 41 is coated with antibodies against the target analyte; the control band 42 is coated with chicken IgY, a quality control antibody.

[0070] Preparation of dissociation pads: The sample pads were made of glass fiber and purchased from Merck Biotechnology. The dissociation pads were soaked in a reagent consisting of buffer, salt, surfactant, alcohol, perfluorooctanoic acid and preservative for 2 hours and then dried for later use.

[0071] Preparation of sample pads: The sample pads are made of glass fiber and were purchased from Merck Biotechnology. The sample pads were soaked in a reagent consisting of buffer, sugars, proteins, surfactants, blocking agents, anti-RBC antibodies, and preservatives for 2 hours and then dried for use.

[0072] Preparation of the conjugate pad: The sample pad was made of glass fiber and purchased from Merck Biotechnology. The conjugate pad was soaked in a reagent consisting of sugars, proteins and buffer for 2 hours and then dried. A certain amount of fluorescent microsphere labeling was sprayed on and dried for later use.

[0073] The preparation of dissociation pads, sample pads, and conjugation pads are all routine procedures known in the field. These materials can be purchased and prepared in-house, or the requirements can be sent to a supplier for provision.

[0074] Comparative Example 1

[0075] Same as in Example 1, except that the length of the dissociation pad 6 is 5 mm.

[0076] Comparative Example 2

[0077] Same as in Example 1, except that the length of the dissociation pad 6 is 12 mm.

[0078] Comparative Example 3

[0079] The test strips in the prior art, namely the test strip of Example 1, do not have a release pad 6, but are otherwise the same.

[0080] The test strips from Example 1 and Comparative Examples 1-3 were subjected to 25-OH VD detection, and the results are as follows:

[0081] Table 1. Detection results of Example 1

[0082]

[0083] Table 2 shows the test results of Comparative Example 3.

[0084]

[0085] Table 3. Detection results of Example 1 and Comparative Examples 1-2

[0086]

[0087] Plot the results from Table 1-2 as follows: Figure 3 As shown in the figure and table, it can be seen that adding the dissociation pad 6 significantly improves the overall signal gradient compared to not having the dissociation pad 6, and the deviation of the concentration values ​​in the test range is significantly smaller.

[0088] from Figure 3 It can be seen that the repeatability is relatively optimal when the size of the dissociation pad is 8 mm*3.8 mm.

[0089] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A test strip comprising a base plate (1), a sample pad (2), a conjugate pad (3), a reaction membrane (4) and a water absorption pad (5) are sequentially arranged on the base plate (1), and the adjacent pads are in contact with each other, characterized in that, A dissociation pad (6) is also provided, which is located downstream of the sample pad (2) and upstream of the conjugate pad (3), and is in contact with the sample pad (2) and the conjugate pad (3) respectively.

2. The test strip of claim 1, wherein, The sample pad (2) overlaps the release pad (6) in whole or in part; The dissociation pad (6) partially overlaps the bonding pad (3).

3. The test strip according to claim 2, characterized in that, The bonding pad (3) partially overlaps the reaction membrane (4), and the absorbent pad (5) partially overlaps the reaction membrane (4).

4. The test strip of any one of claims 2-3, wherein, When partially overlapping, the length of the overlapping area is 1-2mm.

5. The test strip of any one of claims 2-3, wherein, When the sample pad (2) is fully overlapped on the dissociation pad (6), the length of the sample pad (2) is 10-20 mm and the length of the dissociation pad (6) is 22-26 mm. When the sample pad (2) partially overlaps the dissociation pad (6), the length of the dissociation pad (6) is 5-10 mm.

6. The test strip of claim 5, wherein, When the sample pad (2) is fully overlapped on the dissociation pad (6), the length of the sample pad (2) is 10-20 mm and the length of the dissociation pad (6) is 24-25 mm. When the sample pad (2) partially overlaps the dissociation pad (6), the length of the dissociation pad (6) is 7-9 mm.

7. The test strip of claim 5, wherein, The width of the test strip is 3.5-4.2 mm, and the widths of the base plate (1), sample pad (2), conjugate pad (3), reaction membrane (4), absorbent pad (5), and dissociation pad (6) are the same.

8. The test strip of claim 5, wherein, The thickness of the sample pad (2), binding pad (3), reaction membrane (4), absorbent pad (5), and dissociation pad (6) is independently 0.2-0.5 mm.

9. The test strip of claim 1, wherein, The conjugate pad (3) is coated with fluorescently labeled antibodies against the target detection substance; The reaction membrane (4) is provided with a detection band (41) and a quality control band (42). The detection band (41) is coated with an antibody against the target analyte; the quality control band (42) is coated with a quality control antibody.

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