Immunochromatographic testing device

Abstract

This immunochromatographic testing device comprises: a test strip including a test region and a label pad; and a case that accommodates the test strip. The case includes: a cover member having a drip port for dropping a sample liquid onto the label pad; and a case body having a recessed portion that accommodates the test strip, and having, on the inner bottom surface of the recessed portion, a support base that supports the test strip above the inner bottom surface. The immunochromatographic testing device further comprises: a first absorber for absorbing the sample liquid using capillary force, the first absorber being disposed beside the test strip in the width direction in contact with at least a side surface of the label pad and in an orientation extending toward the inner bottom surface of the case body; and a second absorber for absorbing the sample liquid that has leaked out of the first absorber, the second absorber being disposed on the inner bottom surface of the case body in a position spaced apart from the test strip and the first absorber.

Description

Immunochromatographic testing device

[0001] The present disclosure relates to an immunochromatographic testing device.

[0002] Immunological assay methods are widely used as methods for qualitatively or quantitatively measuring test substances present in biological samples such as urine, blood, etc. Among these, immunochromatography is highly convenient because it is easy to operate and enables measurements to be made in a short time.

[0003] Immunochromatography uses a test strip with an antibody (capture antibody) that specifically binds to a test substance (e.g., an antigen) immobilized in a test area. The assay method used in immunochromatography involves spreading a labeled antibody (hereinafter referred to as a labeled antibody) that specifically binds to the antigen and a sample on the test strip, and if the sample contains an antigen, a capture antibody-antigen-labeled antibody complex is formed in the test area. The antigen, which is the test substance, is then measured qualitatively or quantitatively by detecting a signal such as color development due to the labeling of the labeled antibody.

[0004] Test strips are typically housed in a plastic case and provided as immunochromatographic test devices (hereinafter simply referred to as test devices). Test devices include a drop port for dripping sample liquid onto the test strip and a detection window for detecting signals, such as color development by a label. Generally, the appropriate amount of sample liquid to be dripped varies depending on the test device, and this amount is described in the instruction manual. However, when an examiner drips sample liquid, an excessive amount may be dripped. Test strips are equipped with a labeled pad containing labeled antibodies at the sample liquid drip position. The sample liquid dripped onto the labeled pad dissolves the labeled antibodies and then flows through the test strip toward the test area by capillary action. However, if an excessive amount of sample liquid is dripped, some of the sample liquid may not soak into the labeled pad and may flow along the surface of the test strip. This can result in reduced sensitivity or false negative results.

[0005] Japanese Patent Application Laid-Open No. 2016-099283 discloses a testing device in which an absorption section that absorbs sample liquid by capillary action is provided close to the periphery of a sample dropping section, and excess sample liquid dropped in excess is retained in the absorption section, allowing an appropriate amount to flow through the testing strip.

[0006] Japanese Patent Application Laid-Open No. 2019-109207 and Japanese Patent Application Laid-Open No. 2019-109212 propose testing devices equipped with a water-absorbing structure for absorbing sample liquid that has leaked into the device when an excessive amount of sample liquid is dripped.

[0007] In JP 2016-099283 A, the absorbent section is a group of slits integrally formed on the inner surface of the case housing the test strip. It is believed that if the dropped sample liquid is sufficiently excessive, the excess sample liquid can be drawn into the gaps between the slits by the capillary force of the slits. On the other hand, in cases generally formed from resin molded products, the spacing between the slits is much larger than the pore diameter of the labeling pad. Therefore, the capillary force of the slits is inferior to that of the labeling pad. Therefore, if the amount of excess sample liquid is small, the sample liquid cannot be drawn into the gaps between the slits against the capillary force of the labeling pad, and the excess sample liquid may not be prevented from flowing over the surface of the test strip. Furthermore, even if the sample liquid is drawn into the gaps between the slits, the strong capillary force of the labeling pad may return the sample liquid drawn into the slits to the labeling pad, causing the excess sample liquid to spread over the test strip.

[0008] The water-absorbing structure in JP 2019-109207 A and JP 2019-109212 A is intended to absorb excess specimen liquid that leaks from the sample pad and flows along the inner bottom surface of the case the test strip is housed in. JP 2019-109207 A and JP 2019-109212 A do not consider preventing the specimen liquid from flowing along the surface of the test strip toward the test area.

[0009] In either case, when excessive sample liquid is dripped, measures to ensure that the sample liquid that flows along the surface of the test strip toward the test area, or the amount of sample liquid supplied to the test strip, is appropriate are insufficient, and the occurrence of poor judgments cannot be fully suppressed.

[0010] An object of the present disclosure is to provide an immunochromatographic testing device that can provide more reliable determination results than conventional devices, even when an excessive amount of sample liquid is dropped.

[0011] The immunochromatographic testing device of the present disclosure comprises: a test strip having a test area in which sample liquid is developed and a test substance contained in the sample liquid is captured, the test strip having a labeling pad upstream of the test area containing a labeling substance that labels the test substance; a case for accommodating the test strip, the case comprising: a cover member having a drip port for dripping sample liquid onto the labeling pad of the test strip; and a case body having a recess for accommodating the test strip, the case body having a support base on the inner bottom surface of the recess that supports the test strip above the inner bottom surface; a first absorbent body arranged laterally in the width direction of the test strip, in contact with at least the side of the labeling pad and extending toward the inner bottom surface of the case body, the first absorbent body absorbing the sample liquid by capillary force; and a second absorbent body arranged on the inner bottom surface of the case body at a position spaced apart from the test strip and the first absorbent body, absorbing sample liquid leaking from the first absorbent body.

[0012] In the immunochromatographic test device, it is preferable that the amount of liquid that can be held by the first absorbent body is equal to or less than a specified amount to be dropped onto the test strip.

[0013] In the immunochromatographic testing device, the total amount of liquid that can be held by the labeling pad and the first absorbent body is preferably 1 to 2 times the specified amount to be dropped onto the test strip.

[0014] In the immunochromatographic testing device, the first absorbent body is preferably made of the same material as the label pad.

[0015] In the immunochromatographic test device, it is preferable that the only contact area between the first absorbent body and the test strip is the label pad.

[0016] In the immunochromatographic testing device, the first absorbent may contain a labeling substance.

[0017] In the immunochromatographic testing device, the second absorbent body may be made up of a plurality of absorbent bodies arranged around the first absorbent body.

[0018] In an immunochromatographic testing device, it is preferable that the second absorbent body has a length equal to or greater than the length of the first absorbent body along the longitudinal direction of the test strip, and is arranged longitudinally along the longitudinal direction and opposite the first absorbent body.

[0019] In the immunochromatographic testing device, the first absorbent body may be in contact with the inner bottom surface of the case body.

[0020] In the immunochromatographic testing device, the first absorbent body may be disposed apart from the inner bottom surface of the case body, and the second absorbent body may be disposed directly below the first absorbent body.

[0021] In the immunochromatographic testing device, the second absorbent body preferably has a shape that surrounds the periphery of the first absorbent body.

[0022] In the immunochromatographic testing device, the second absorber is preferably disposed at a position within 1 mm of the first absorber.

[0023] In the immunochromatographic test device, the first absorbent body and the second absorbent body are preferably disposed on both sides of the test strip.

[0024] According to the immunochromatographic testing device of the present disclosure, even when an excessive amount of sample liquid is dropped, a determination result with higher reliability than conventional ones can be obtained.

[0025] 8A is a perspective view of a testing device; FIG. 8B is an exploded perspective view of a testing device; FIG. 8C is a cutaway side view of a testing device; FIG. 8D is a cutaway side view of a testing device showing a state in which a first pressing operation unit is pressed in; FIG. 8E is a cutaway side view of a testing device showing a state in which a second pressing operation unit is pressed in addition to the first pressing operation unit; FIG. 8F is a diagram showing the procedure of an immunochromatographic test using a testing device; FIG. 8G is a perspective view showing the positional relationship between a test strip, a first absorbent body, and a second absorbent body within a testing device; FIG. 8H is an enlarged plan view of the periphery of a label pad of the testing device shown in FIG. 7, and FIG. 8H is a cutaway side view of the periphery of the label pad of the testing device shown in FIG. 7 along line BB; FIG. 8I is a cross-sectional view taken along line IX-IX in FIG. 8A; FIG. 8I is an explanatory diagram of a contact portion between a first absorbent body and a test strip; FIG. 8H is a diagram showing modified examples of the first absorbent body and the second absorbent body, and FIG. 8I is an enlarged plan view of the periphery of a label pad of the testing device along line BB; and FIG. 8I is a cutaway side view of the periphery of the label pad of the testing device along line BB. Fig. 1 shows modified examples of the first absorbent body and the second absorbent body, where (a) is an enlarged plan view of the periphery of a marker pad of the testing device, and (b) is a side view cut along line b-b. Fig. 2 shows modified examples of the first absorbent body and the second absorbent body, where (a) is an enlarged plan view of the periphery of a marker pad of the testing device, and (b) is a side view cut along line b-b. Fig. 3 shows modified examples of the first absorbent body and the second absorbent body, where (a) is an enlarged plan view of the periphery of a marker pad of the testing device, and (b) is a side view cut along line b-b.

[0026] Hereinafter, an immunochromatographic testing device (hereinafter referred to as a testing device) according to an embodiment of the present invention will be described with reference to the drawings. Components indicated by the same reference numerals in the various drawings are the same components.

[0027] Fig. 1 is an external view of a testing device 10 according to one embodiment, and Fig. 2 is an exploded perspective view of the testing device 10. Fig. 3 is a cutaway side view of the testing device 10, Fig. 4 is a cutaway side view of the testing device 10 showing a state in which a first pressing operation unit 19 is pressed in, and Fig. 5 is a cutaway side view of the testing device 10 showing a state in which a second pressing operation unit 20 is pressed in addition to the first pressing operation unit 19. Fig. 6 is a diagram showing the procedure for an immunochromatographic test using the testing device 10.

[0028] The testing device 10 is a single-use device that is used one for each sample to be tested. As shown in Figures 1 and 2, the testing device 10 includes a test strip 14 and a case 11 that houses the test strip 14. In addition to the test strip 14, the case 11 also houses a first absorbent body 21, a second absorbent body 22 (see Figure 7), a first reagent holder 45, a second reagent holder 52, and the like.

[0029] The test strip 14 has a test area L1 in which a sample liquid 72 (see FIG. 6) is developed and which captures a test substance 73 (see FIG. 6) contained in the sample liquid 72. The test area L1 changes color depending on whether the sample contains the test substance 73, i.e., whether the sample is positive or negative. The testing device 10 is configured so that a user can visually check the change in color to determine whether the sample is positive or negative.

[0030] The testing device 10 of this example is characterized by being equipped with a first absorbent body 21 and a second absorbent body 22, but details of the first absorbent body 21 and the second absorbent body 22 will be explained after explaining the basic structure and basic usage method of the testing device 10.

[0031] The case 11 has an elongated rectangular parallelepiped shape and is composed of a case body 12 and a cover member 13. The case body 12 is a box having a recess that forms a storage space surrounded by a bottom plate in the shape of an elongated rectangular plate and four side plates that extend perpendicularly from the four sides of the bottom plate. The inner bottom surface 12A (see FIG. 7 ) of the storage space of the case body 12 is the “inner bottom surface of the case body” according to the technology of the present disclosure.

[0032] Convex support bases 35-37 on which the test strip 14 is placed are formed on the inner bottom surface 12A of the case body 12. The support base 35 is provided in the center of the case body 12. The support base 36 is provided at one end of the case body 12 on the downstream side in the development direction of the sample liquid 72. The support bases 35 and 36 are at the same height. The support base 37 is provided at the other end of the case body 12 on the upstream side in the development direction of the sample liquid 72. The support base 37 is at the same height as the support bases 35 and 36. The test strip 14 is placed on the support bases 35-37. The support bases 35-37 support the test strip 14 above the inner bottom surface 12A.

[0033] The cover member 13 has the same elongated rectangular plate shape as the bottom plate of the case body 12, and functions as a lid that covers the storage space of the case body 12. The surface of this cover member 13 is the surface 16 of the case 11. Note that the X and Y directions shown in the figure are both directions along a horizontal plane and are perpendicular to each other. The X direction is the direction along the short side of the case 11, and is the so-called left-right direction. The Y direction is the direction along the long side of the case 11, and is the so-called front-back direction. The Z direction is the direction along the vertical direction and is perpendicular to the X and Y directions. The Z direction is the so-called up-down direction. In each figure, the directions indicated by arrows X, Y, and Z are assumed to coincide with each other.

[0034] The cover member 13 is formed with a drip port 17 and an observation window 18. The cover member 13 is also provided with a first pressing operation unit 19 and a second pressing operation unit 20. The drip port 17, observation window 18, first pressing operation unit 19, and second pressing operation unit 20 are integrally molded.

[0035] The drip port 17 is a round hole through which a specimen liquid 7272 (see FIG. 6) containing a specimen is dripped, and has a boss-like edge that protrudes from the surface 16. The drip port 17 is formed in the center of the cover member 13. The drip port 17 is an opening for dripping the specimen liquid 72 into the case 11. In the test strip 14 inside the case 11, the label pad 31 is positioned opposite the drip port 17, and the specimen liquid 72 dripped from the drip port 17 is applied to the label pad 31. The specimen is not particularly limited as long as it can contain the test substance 73 (see FIG. 6). The specimen includes biological samples from individuals, particularly animals, and even humans, who are the subject of the immunochromatographic test, such as blood, serum, plasma, cerebrospinal fluid, tears, sweat, urine, feces, pus, nasal discharge, nasal swabs, throat swabs, nasal aspirates, or sputum, as well as organs, tissues, mucous membranes, and skin, or swabs containing these, or animals or plants themselves or their dried forms. Examples of the test substance 73 include antigens, antibodies, proteins, and low-molecular-weight compounds.

[0036] As shown in FIG. 3 , the sample liquid 72 is contained in a dropper 25 that can accommodate at least a specified amount to be dropped onto the test strip 14, and is dropped from the drop port 17 using the dropper 25. The "specified amount to be dropped onto the test strip 14" refers to an appropriate amount of sample liquid that is predetermined for each testing device 10. The amount of sample liquid 72 that is optimal for testing is determined as the specified amount for each testing device 10. The testing device 10 is configured to obtain accurate test results by performing the test with the specified amount. Generally, for commercially available testing devices, the specified amount is described in its instruction manual. Although a specific numerical value may be described as the specified amount, for example, the dropper 25 described below may be provided as an accessory with the testing device, and the instruction manual may state, for example, "drop one drop from the drop port 17 using the dropper 25." In such cases, one drop dropped by the accessory dropper 25 is the specified amount.

[0037] The dripping device 25 is, for example, composed of a container 26 containing a specimen treatment liquid such as an extractant, and a nozzle 27 that fits into the opening of the container 26. For example, the specimen is extracted by immersing a swab containing the specimen in the specimen treatment liquid in the container 26. In this example, the specimen liquid 72 is a dissolving liquid in which the specimen is dissolved in the specimen treatment liquid.

[0038] The observation window 18 is a rectangular opening for externally observing the test area L1 and the like of the test strip 14. The observation window 18 is formed between the drip port 17 and the second pressing operation unit 20.

[0039] The first pressing operation unit 19 is provided at one end in the Y direction of the cover member 13. The first pressing operation unit 19 is pressed by a user when supplying a first reagent 48 (see FIG. 3 ) to the test strip 14. The second pressing operation unit 20 is provided at the other end in the Y direction of the cover member 13 on the opposite side to the first pressing operation unit 19. The second pressing operation unit 20 is pressed by a user when supplying a second reagent 55 (see FIG. 3 ) to the test strip 14.

[0040] The test strip 14 has an overall elongated rectangular plate shape, and includes a carrier 30, a label pad 31, a liquid delivery pad 32, an absorbent pad 33, and a back adhesive sheet 34.

[0041] The carrier 30 is made of a porous, insoluble material such as a nitrocellulose membrane. The label pad 31 is attached to the carrier 30 at a position opposite the dropping port 17. As described above, the sample liquid 72 dropped into the dropping port 17 is deposited on the label pad 31. In other words, the label pad 31 functions as a deposition area for the sample liquid 72.

[0042] The sample liquid 72 dispensed on the label pad 31 penetrates the carrier 30 and spreads toward one end of the carrier 30 in the Y direction due to capillary action. The test region L1, control region L2, and color development region L3 are provided at one end of the carrier 30 in the Y direction where the sample liquid 72 spreads. The test region L1, control region L2, and color development region L3 are strip-shaped regions extending from one end of the carrier 30 to the other end in the X direction. If the direction from the label pad 31 toward the test region L1, etc. is defined as the spreading direction of the sample liquid 72 (see FIG. 3 ), the test region L1 is located at the most upstream side of the spreading direction, and the color development region L3 is located at the most downstream side of the spreading direction. The control region L2 is located between the test region L1 and the color development region L3. In other words, the control region L2 is located downstream of the test region L1 and upstream of the color development region L3. In Fig. 2, the test region L1, the control region L2, and the color-developing region L3 are hatched, but this hatching is done for the convenience of explanation and does not indicate that each of the regions L1 to L3 is colored. The same applies to Figs. 3 to 5 below.

[0043] The liquid supply pad 32 is attached to one end of the carrier 30 opposite to the other end where the test region L1, etc. are provided. The liquid supply pad 32 is formed from a porous material similar to the carrier 30, etc., and supplies the first reagent 48 to the carrier 30 by capillary action.

[0044] The absorbent pad 33 is attached to one end of the carrier 30 where the test region L1 and the like are provided. The absorbent pad 33 is also made of a porous material. The absorbent pad 33 absorbs the sample liquid 72, first reagent 48, and second reagent 55 that have been spread on the carrier 30. By actively absorbing the sample liquid 72 and the like in this way, the speed at which the sample liquid 72 and the like are spread is increased.

[0045] The back adhesive sheet 34 is a substrate having an adhesive surface, to which the carrier 30 is adhesively fixed. The back adhesive sheet 34, and therefore the test strip 14, are placed on convex support bases 35 to 37 formed in the storage space of the case body 12.

[0046] A concave first storage section 38 is formed in a support base 37 formed in the storage space of the case body 12. The first storage section 38 is provided at a position facing the other end of the liquid supply pad 32 attached to the carrier 30, opposite the one end attached to the carrier 30. A first reagent holding section 45 is stored in the first storage section 38.

[0047] The first reagent holding unit 45 is composed of a container 46 having an opening on one side and a seal 47 that liquid-tightly covers the opening of the container 46. The container 46 is made of, for example, a resin material. A first reagent 48 is stored inside the container 46. The seal 47 is, for example, an aluminum sheet, and can be easily broken with a sharp blade or the like. The first reagent holding unit 45 is housed in the first housing unit 38 with the seal 47 facing upward so that the seal 47 faces the other end of the liquid delivery pad 32.

[0048] A multi-function member 49 is disposed on the upper portion of the support base 36. The multi-function member 49 is formed of a transparent resin material, such as acrylic resin. The multi-function member 49 is a member in which a second storage section 50 and a flow path forming section 51 are integrally provided. The second storage section 50 is a box with an open top, and a second reagent holding section 52 is housed inside. The flow path forming section 51 is a flat plate extending in the Y direction from the bottom of the second storage section 50. The flow path forming section 51 extends to just before the labeling pad 31 and covers the upper portions of the test region L1, control region L2, and color development region L3 of the carrier 30. A gap G is provided between the carrier 30 and the flow path forming section 51 (see FIG. 3). The gap G is, for example, in the range of 0.01 mm to 1 mm. By providing the gap G between the carrier 30 and the flow path forming section 51 in this manner, a flow path for the second reagent 55 is secured.

[0049] The second reagent holding unit 52 is composed of a container 53 having an opening on one side and a seal 54 that liquid-tightly covers the opening of the container 53. The container 53 is made of, for example, a resin material. A second reagent 55 is stored inside the container 53. The seal 54 is, for example, an aluminum sheet, and can be easily broken with a sharp blade or the like. The second reagent holding unit 52 is housed in the second housing unit 50 with the seal 54 facing downward so that it faces the test strip 14.

[0050] 3, the first pressing operation unit 19 is provided with a first breaking protrusion 60. The second pressing operation unit 20 has a second reagent holding unit 52 attached to its inner surface. The second storage unit 50 has a bottom portion provided with a second breaking protrusion 61 and a supply port 62. The first breaking protrusion 60 and the second breaking protrusion 61 have sharp tips.

[0051] As shown in FIG. 4 as an example, when the first pressing operation unit 19 is pressed, the first breaking protrusion 60 comes into contact with the other end of the liquid supply pad 32 and pushes the other end of the liquid supply pad 32 toward the seal 47 of the first reagent holder 45. This pushing of the other end of the liquid supply pad 32 by the first breaking protrusion 60 breaks the seal 47, causing the other end of the liquid supply pad 32 to drop into the container 46 and become immersed in the first reagent 48. The first reagent 48 is developed from the other end of the liquid supply pad 32 toward the carrier 30 by capillary action. The first pressing operation unit 19 maintains its compressed state even after being compressed by the pressing operation. Therefore, development of the first reagent 48 continues until substantially all of the first reagent 48 is absorbed into the liquid supply pad 32.

[0052] 5, when the second pressing operation unit 20 is pressed, the second reagent holding unit 52 moves downward within the second storage unit 50 and reaches the bottom of the second storage unit 50, where the second breaking protrusion 61 is located. The seal 54 of the second reagent holding unit 52 is then broken by the second breaking protrusion 61. The second reagent 55 stored in the second reagent holding unit 52 flows from the broken portion of the seal 54 to the supply port 62, and then flows through the flow path secured by the gap G (see FIG. 3) to be supplied to the carrier 30.

[0053] As an example, as shown in FIG. 6 , the labeling pad 31 contains a labeling substance 70. The labeling substance 70 is modified with a first binding substance 71. The first binding substance 71 specifically binds to an analyte 73 contained in a sample solution 72. In this embodiment, for example, gold colloid particles (manufactured by BBI Solutions, product code: EM.GC50) with a diameter of 50 nm are used as the labeling substance 70. Note that the labeling substance 70 is not limited to gold colloid particles, and may be metal sulfides used in immunochromatography or colored particles used in immunoagglutination reactions, among others. Metal colloids are particularly preferred. In addition to the above-mentioned gold colloids, examples of metal colloids include silver colloids, platinum colloids, iron colloids, aluminum hydroxide colloids, and composite colloids thereof. In particular, gold colloids are preferred because they exhibit a red color and silver colloids exhibit a yellow color at appropriate particle sizes, with gold colloids being the most preferred.

[0054] For example, if test substance 73 is an antigen, first binding substance 71 is an antibody to the antigen, and if test substance 73 is an antibody, first binding substance 71 is an antigen to the antibody. If test substance 73 is a protein, a low molecular weight compound, or the like, first binding substance 71 is an aptamer to the protein, the low molecular weight compound, or the like.

[0055] Test area L1 contains a second binding substance 74. The second binding substance 74 specifically binds to the analyte 73 to which the first binding substance 71 is bound. This causes the analyte 73 to be captured in test area L1. When the analyte 73 is captured, the color density of test area L1 rises above a preset standard. When the color density of test area L1 rises above the standard, it is determined that the sample contains the analyte 73, i.e., the sample is positive.

[0056] Before the specimen liquid 72 is developed, the test area L1 is substantially the same color (e.g., white) as the carrier 30. When the specimen liquid 72 is developed and the developed specimen liquid 72 contains the test substance 73, i.e., when the specimen is positive, the color density of the test area L1 increases, and the test area L1 appears as a line. The test area L1 develops a black color due to amplified silver amplification, which will be described later.

[0057] The change in the color state of the test region L1 includes any of a color change, color development, and density change. A color change is a change from a first color different from the color of the carrier 30 to a second color. A color development is a change in the color of the carrier 30 to a different color due to the development of a color different from the color of the carrier 30. A density change is a change in the density of a color.

[0058] Like the first binding substance 71, for example, if the test substance 73 is an antigen, the second binding substance 74 is an antibody against the antigen, and if the test substance 73 is an antibody, the second binding substance 74 is an antigen against the antibody. If the test substance 73 is a protein, a low molecular weight compound, or the like, the second binding substance 74 is an aptamer against the protein, the low molecular weight compound, or the like. The first binding substance 71 and the second binding substance 74 may be the same or different. For example, if the test substance 73 is an influenza A virus or a biomarker thereof, an anti-influenza A monoclonal antibody (manufactured by Medix Biochemica, product name: Anti-Influenza A SPT N-5 7307) can be used as the first binding substance 71 and the second binding substance 74.

[0059] The control region L2 contains a third binding substance 75. The third binding substance 75 specifically binds to the first binding substance 71. This causes the labeled substance 70 to be captured in the control region L2. Some labeled substances 70 have first binding substances 71 that do not bind to the test substance 73. Such labeled substances 70 reach the control region L2 without being captured in the test region L1, and are captured in the control region L2. When the labeled substance 70 is captured, the color density of the control region L2 increases to or above a preset standard. When the color density of the control region L2 increases to or above the standard, it is determined that the sample liquid 72 has been sufficiently developed on the carrier 30, and that development of the sample liquid 72 is complete.

[0060] Like the test region L1, the control region L2 is substantially the same color (e.g., white) as the carrier 30 before the sample liquid 72 is developed. The control region L2 appears as a line due to an increase in color density when the labeled substance 70 is captured. The control region L2 also develops a black color due to being amplified by silver amplification, which will be described later.

[0061] The third binding substance 75 may be the analyte 73 itself, or may be a compound having a site recognized by the first binding substance 71. Examples of compounds having a site recognized by the first binding substance 71 include compounds in which a derivative of the analyte 73 is bound to a protein. For example, when the analyte 73 is influenza A virus or a biomarker thereof, an anti-mouse IgG antibody (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name: anti-mouse IgG (H+L), rabbit F(ab')2, product code: 566-70621) can be used as the third binding substance 75.

[0062] The color-developing region L3 contains a substance (not shown) that changes color upon reaction with the first reagent 48. When the color-developing region L3 reacts with the first reagent 48 and develops color or changes color, it indicates that the first reagent 48 has spread to the color-developing region L3 and that it is time to begin supplying the second reagent 55. For example, when a mixed aqueous solution of iron nitrate and citric acid (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd., product code: 038-06925) is used as the first reagent 48, it is preferable to form the color-developing region L3 with a color-developing reagent immobilization line in which Bromocresol Green (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) is immobilized in a strip-like shape. In this case, the color-developing region L3 is dark green before reacting with the first reagent 48 and changes color to orange upon arrival of the first reagent 48.

[0063] The first reagent 48 and the second reagent 55 are amplification solutions that react with each other to amplify the color development in the test area L1 and the control area L2. When a metal-based substance such as gold colloid particles is used as the labeled substance 70, as in this example, silver amplification is used as a method for amplifying the color development. The first reagent 48 and the second reagent 55 are amplification solutions used for silver amplification, as an example. The reaction of the first reagent 48 and the second reagent 55 with the labeled substance 70 as a catalyst is the amplification reaction. The amplification reaction produces silver particles 76 that are relatively larger in particle size than the labeled substance 70.

[0064] More specifically, the first reagent 48 is a solution of a reducing agent that reduces silver ions, and the second reagent 55 is a solution of silver ions. When the reducing agent in the first reagent 48 and the silver ions in the second reagent 55 are brought into contact with the labeled substance 70, silver particles 76 are generated. The silver particles 76 deposit on the labeled substance 70, using the labeled substance 70 as a nucleus. The silver particles 76 deposited on the labeled substance 70 ultimately have a particle diameter several tens to several hundreds times larger than that of the labeled substance 70. This amplifies the labeled signal emitted by the labeled substance 70, and as a result, the color development in the test region L1 and the control region L2 is amplified.

[0065] The reducing agent of the first reagent 48 can be any inorganic or organic material or a mixture thereof, as long as it can reduce silver ions to silver. ２＋ , V ２＋ Or Ti ３＋ Preferred examples of reducing metal salts and reducing metal complex salts are those whose valence can be changed by metal ions such as Fe. When using an inorganic reducing agent, it is necessary to form a complex or reduce the oxidized ions, thereby removing or rendering them harmless. For example, Fe ２＋ When using as a reducing agent, the oxide Fe is reduced using citric acid or ethylenediaminetetraacetic acid (EDTA). ３＋ In this example, it is preferable to use such an inorganic reducing agent as the reducing agent, and more preferably, Fe ２＋ Metal salts of the formula are preferred.

[0066] Developing agents used in wet silver halide photographic light-sensitive materials (e.g., methyl gallate, hydroquinone, substituted hydroquinone, 3-pyrazolidones, p-aminophenols, p-phenylenediamines, hindered phenols, amidoximes, azines, catechols, pyrogallols, ascorbic acid (or its derivatives), and leuco dyes), and other materials obvious to those skilled in the art, such as those described in U.S. Pat. No. 6,020,117, can also be used as reducing agents.

[0067] Ascorbic acid reducing agents are also preferred as reducing agents. Useful ascorbic acid reducing agents include ascorbic acid, analogs, isomers, and derivatives thereof. Preferred examples include D- or L-ascorbic acid and its sugar derivatives (e.g., γ-lactoascorbic acid, glucoascorbic acid, fucoascorbic acid, glucoheptoascorbic acid, and maltoascorbic acid), sodium ascorbic acid, potassium ascorbic acid, isoascorbic acid (or L-erythroascorbic acid), salts thereof (e.g., alkali metal salts, ammonium salts, or salts known in the art), enediol-type ascorbic acid, enaminol-type ascorbic acid, and thioenol-type ascorbic acid. D-ascorbic acid or L-ascorbic acid (and alkali metal salts thereof) or isoascorbic acid (or alkali metal salts thereof) are particularly preferred, with sodium salts being preferred. Mixtures of these reducing agents can be used if necessary.

[0068] The second reagent 55 is preferably one in which a silver ion-containing compound is dissolved in a solvent. The silver ion-containing compound may be an organic silver salt, an inorganic silver salt, or a silver complex. Preferably, it is an inorganic silver salt or a silver complex. As the inorganic silver salt, a silver ion-containing compound that is highly soluble in a solvent such as water may be used, such as silver nitrate, silver acetate, silver lactate, silver butyrate, or silver thiosulfate. Silver nitrate is particularly preferred. As the silver complex, a silver complex coordinated with a ligand having a water-soluble group such as a hydroxyl group or a sulfonic acid group is preferred, such as silver hydroxythioether.

[0069] The procedure for immunochromatographic testing using the testing device 10 will be described with reference to Fig. 6. Here, the case where the sample contains the test substance 73, that is, the sample is positive, will be described as an example. Note that the back adhesive sheet 34 is not shown in Fig. 6.

[0070] First, as shown in step ST1, a sample liquid 72 is applied to the labeling pad 31. The analyte 73 in the sample liquid 72 applied to the labeling pad 31 specifically binds to the first binding substance 71 that modifies the labeling substance 70 in the labeling pad 31. The sample liquid 72 permeates from the labeling pad 31 into the carrier 30 and is spread by capillary action toward the test region L1 and other regions (downstream), as shown by arrow 80. A portion of the sample liquid 72 is also spread toward the liquid supply pad 32 (upstream), as shown by arrow 81.

[0071] Next, as shown in step ST2, the first reagent 48 is supplied by pressing the first pressing operation unit 19. As shown by arrow 82, the first reagent 48 is supplied from the liquid supply pad 32 to the carrier 30 and spreads to the side (downstream side) of the test region L1, etc. by capillary action.

[0072] Thereafter, as shown in step ST3, the sample liquid 72, the labeling substance 70, and the first reagent 48 continue to develop. The sample liquid 72 and the labeling substance 70 developing from the labeling pad 31 are swept away by the first reagent 48 and developed toward the test region L1, etc. As shown in step ST4, the first reagent 48 eventually reaches the color-developing region L3. The color-developing region L3 reacts with the first reagent 48 and changes color. In this example, the color-developing region L3 is dark green before reacting with the first reagent 48, and changes color to orange upon reacting with the first reagent 48.

[0073] The analyte 73 that has reached the test region L1, more specifically, the labeled substance 70 that has bound to the analyte 73 via the first binding substance 71, is captured by the second binding substance 74 in the test region L1. This causes the color density in the test region L1 to rise above the reference level. On the other hand, the labeled substance 70 that has not bound to the analyte 73 passes through the test region L1 without being captured by the second binding substance 74, and is captured by the third binding substance 75 in the control region L2. This causes the color density in the control region L2 to rise above the reference level.

[0074] The user presses the first pressing operation unit 19 to spread the first reagent 48, and then waits until the first reagent 48 reaches the color-developing region L3 and the color state of the color-developing region L3 changes (steps ST3 and ST4). When the user visually confirms through the observation window 18 that the color state of the color-developing region L3 has changed, the user presses the second pressing operation unit 20.

[0075] As shown in step ST5, pressing the second pressing operation unit 20 supplies the second reagent 55. As indicated by arrow 83, the second reagent 55 is supplied to the carrier 30 from downstream of the color-developing region L3 and spreads toward the liquid supply pad 32 (upstream). As shown in step ST6, the silver ions contained in the second reagent 55 and the reducing agent contained in the first reagent 48 generate silver particles 76, with the labeled substance 70 captured in the test region L1 and the control region L2 acting as nuclei. The silver particles 76 amplify the color development in the test region L1 and the control region L2. In this way, the testing device 10 is configured to allow the user to visually determine whether the sample is positive. The testing device 10 can also be used in a manner in which it is loaded into a testing device that determines whether the sample is positive, and the testing device displays the test results.

[0076] As described above, the testing device 10 further includes a first absorbent body 21 and a second absorbent body 22 inside the case body 12 .

[0077] The arrangement and function of the first absorbent body 21 and the second absorbent body 22 in the testing device 10 will be described in detail with reference to Figure 7 and subsequent figures. Figure 7 is a diagram showing the arrangement of the first absorbent body 21 and the second absorbent body 22 in the case main body 12 of the testing device 10 shown in Figures 1 to 5. Figure 8(a) is an enlarged plan view of the vicinity of the marked pad 31 surrounded by dashed line a in Figure 7, and Figure 8(b) is a cross-sectional view taken along line b-b in Figure 8(a). Figure 9 is a cross-sectional view taken along line IX-IX in Figure 8(a).

[0078] As shown in Fig. 7, the first absorbent body 21 is disposed laterally in the width direction of the test strip 14 in a position in contact with at least the side surface of the marking pad 31. Furthermore, as shown in Figs. 8 and 9, the first absorbent body 21 is disposed in a position in which it extends toward the inner bottom surface 12A of the case main body 12. "Extending toward the inner bottom surface 12A" means that, as shown in Fig. 8(b), the lower end 21a of the first absorbent body 21 in the vertical direction is positioned at least on the back surface of the test strip 14, i.e., closer to the inner bottom surface 12A than the back surface 34A of the back adhesive sheet 34. In Fig. 8, the lower end 21a of the first absorbent body 21 does not contact the inner bottom surface 12A of the case main body 12, but the lower end 21a of the first absorbent body 21 may contact the inner bottom surface 12A.

[0079] 9, the first absorbent body 21 is disposed so that its thickness direction coincides with the width direction (X direction in the drawing) of the test strip 14. In this example, the first absorbent body 21 is disposed so that its vertical length La is longer than its horizontal length (i.e., sheet thickness) Lb.

[0080] The first absorbent body 21 absorbs at least a portion of the sample liquid 72 dropped onto the label pad 31. The first absorbent body 21 is made of a porous material, and absorbs the sample liquid 72 by capillary force from the portion that comes into contact with the label pad 31. In particular, when a volume of sample liquid 72 greater than a specified volume is dropped onto the label pad 31, the first absorbent body 21 absorbs the excess sample liquid 72 that cannot be absorbed by the label pad 31.

[0081] The sample liquid 72 absorbed by the first absorbent body 21 moves vertically downward as shown by arrow 86 in Figure 8(b) due to capillary force and / or its own weight within the first absorbent body 21. As the amount of sample liquid 72 within the first absorbent body 21 increases, the sample liquid 72 is transported vertically downward within the first absorbent body 21, leaks out from the lower end 21a, and spreads onto the inner bottom surface 12A of the case body 12.

[0082] The second absorbent body 22 is disposed on the inner bottom surface 12A of the case body 12 at a position spaced apart from the test strip 14 and the first absorbent body 21. "Disposed at a position spaced apart from the test strip 14 and the first absorbent body 21" means that the second absorbent body 22 is not in contact with either the test strip 14 or the first absorbent body 21. The distance D between the second absorbent body 22 and the first absorbent body 21 is preferably within 1 mm. The distance D is the shortest distance between the first absorbent body 21 and the second absorbent body 22. The second absorbent body 22 absorbs the sample liquid 72 leaking from the first absorbent body 21, i.e., the sample liquid 72 leaking from the first absorbent body 21 and spreading on the inner bottom surface 12A. In FIG. 8(b), arrow 87 indicates the movement of the sample liquid 72 leaking onto the inner bottom surface 12A as it is absorbed by the second absorbent body 22.

[0083] As described above, the testing device 10 of this embodiment includes a first absorbent body 21 disposed laterally in the width direction of the test strip 14, in contact with at least the side surface of the label pad 31, and extending toward the inner bottom surface 12A of the case body 12. The first absorbent body 21 absorbs the sample liquid 72 by capillary force. Because the first absorbent body 21 is in contact with the label pad 31, an excess of the sample liquid 72 drips onto the label pad 31, and any sample liquid 72 that is not absorbed by the label pad 31 can be drawn into the first absorbent body 21. The first absorbent body 21 is disposed in a position extending toward the inner bottom surface 12A of the case body 12, i.e., has a portion that is positioned vertically lower than the back surface of the test strip 14. Therefore, the sample liquid 72 drawn into the first absorbent body 21 from the label pad 31 descends vertically downward toward the inner bottom surface 12A due to its own weight and leaks out onto the inner bottom surface 12A. Therefore, the first absorbent body 21 always has a sufficient capillary force to absorb the sample liquid 72, and the capillary force at the portion above the inner bottom surface 12A that is in contact with the labeled pad 31 does not decrease, allowing the first absorbent body 21 to quickly draw in any excess sample liquid 72. This prevents the sample liquid 72 from flowing over the test strip 14 when an excess amount of sample liquid 72 is dripped.

[0084] Furthermore, the testing device 10 includes a second absorbent body 22 disposed on the inner bottom surface 12A of the case body 12 at a position spaced apart from the test strip 14 and the first absorbent body 21, and this second absorbent body 22 absorbs the sample liquid 72 that leaks from the first absorbent body 21. In this way, the sample liquid 72 that cannot be retained by the first absorbent body 21 and leaks onto the inner bottom surface 12A is absorbed by the second absorbent body 22. Because the second absorbent body 22 is disposed at a distance from the first absorbent body 21 and the test strip 14, the sample liquid 72 absorbed by the second absorbent body 22 does not return to the test strip 14. Therefore, it is possible to prevent excess sample liquid 72 from being supplied to the test strip 14.

[0085] In this way, the testing device 10 includes the first absorbent body 21 and the second absorbent body 22, and therefore can suppress poor determinations such as reduced sensitivity or false negatives compared to conventional testing devices that do not include the first absorbent body 21 and the second absorbent body 22. As a result, the testing device 10 can obtain highly reliable determination results.

[0086] Furthermore, since the configuration prevents excess specimen liquid 72 from returning to the test strip 14, there is also the effect of suppressing delays in test time in a testing device 10 of the present embodiment, which is a type that develops a reagent such as a reducing agent a certain time after the specimen liquid 72 is dropped.

[0087] As described with reference to FIG. 6 , in the testing device 10 of this embodiment, the sample liquid 72 deposited on the label pad 31 is spread in the test strip 14 toward the test area L1 (downstream side) and toward the liquid supply pad 32 (upstream side). If an excessive amount is dispensed, the amount of liquid spreading upstream also increases. After the sample liquid 72 is dispensed, the first reagent 48 is supplied by pressing the first pressing operation unit 19. However, if a large amount of the sample liquid 72 spreads upstream, the first reagent 48 does not spread as quickly, leading to a delay in the test time. By providing the first absorbent 21, the excess sample liquid 72 can be absorbed, thereby preventing the excess sample liquid 72 from being supplied to the test strip 14. On the other hand, if the excess sample liquid 72 absorbed by the second absorbent body 22 comes into contact with at least one of the first absorbent body 21 and the test strip 14, the sample liquid 72 in the second absorbent body 22 may be reabsorbed due to capillary forces of the first absorbent body 21 or the carrier 30 of the test strip 14. If the amount of sample liquid 72 supplied to the test strip 14 increases due to reabsorption, the development of the first reagent 48 will be delayed, which will also lead to a delay in the test time. However, as described above, in the testing device 10 of this embodiment, the second absorbent body 22 is not in contact with either the first absorbent body 21 or the test strip 14, so reabsorption of the sample liquid 72 absorbed by the second absorbent body 22 into the test strip 14 can be suppressed. Therefore, the testing device 10 has the effect of suppressing delays in the test time.

[0088] Furthermore, in the testing device 10, if the second absorbent body 22 is positioned within 1 mm of the first absorbent body 21, the excess sample liquid 72 leaking from the first absorbent body 21 can be quickly absorbed by the second absorbent body 22.

[0089] In the testing device 10 , it is preferable that the amount of liquid that can be held by the first absorbent body 21 is equal to or less than the specified amount that should be dropped onto the testing strip 14 .

[0090] Because the first absorbent body 21 is in contact with the label pad 31, when the sample liquid 72 in the label pad 31 flows downstream of the test strip 14, the label pad 31 draws the sample liquid 72 from the first absorbent body 21 by its capillary force and supplies it into the test strip 14. If the amount of liquid that can be held by the first absorbent body 21 is equal to or less than a specified amount, excess sample liquid 72 can be more effectively prevented from flowing into the test strip 14. Note that when the first absorbent body 21 is made up of multiple absorbents, it is preferable that the total amount of liquid that can be held by the multiple absorbents is equal to or less than the above-mentioned specified amount.

[0091] It is preferable that the total amount of liquid that can be held by the label pad 31 and the first absorbent body 21 is 1 to 2 times the specified amount to be dropped onto the test strip 14. When the first absorbent body 21 is composed of multiple absorbents as in the case described above, it is preferable that the amount of liquid that can be held by the label pad 31 and the multiple absorbents that make up the first absorbent body 21 is 1 to 2 times the specified amount.

[0092] The amount of sample flowing through the test strip 14 can be reliably reduced to less than twice the specified amount, thereby providing highly reliable determination results.

[0093] It is preferable that the first absorbent body 21 has a capillary force equal to or less than that of the marker pad 31. For example, if the first absorbent body 21 is made of the same material as the marker pad 31, it can have a capillary force equal to that of the marker pad 31.

[0094] If the material of the first absorbent 21 is the same as the material of the labeled pad 31, the sample liquid 72 can be sucked up by the same capillary force as the labeled pad 31 when it is dripped, and if excess sample liquid 72 is dripped onto the labeled pad 31, the sample liquid 72 can be sucked up efficiently, effectively preventing the excess sample liquid 72 from flowing over the surface of the test strip 14.

[0095] If the capillary force of the first absorbent body 21 is equal to or less than that of the label pad 31, the sample liquid 72 held in the first absorbent body 21 will be more likely to return to the label pad 31 side.

[0096] Furthermore, the first absorbent body 21 may contain the labeling substance 70 contained in the labeling pad 31. If the first absorbent body 21 is in contact not only with the labeling pad 31 but also, for example, with the carrier 30, the sample liquid 72 in the first absorbent body 21 may be returned to the carrier 30 from the first absorbent body 21 by the capillary force of the carrier 30 without returning to the labeling pad 31. In such a case, the sample liquid 72 and the labeling substance 70 may not be brought into sufficient contact with each other, and the labeling of the test substance 73 may be insufficient. However, if the first absorbent body 21 contains the labeling substance 70, the test substance 73 and the labeling substance 70 can be brought into sufficient contact with each other even when the sample liquid 72 is returned to the test strip 14 without passing through the labeling pad 31.

[0097] As described above, the first absorbent body 21 has the function of absorbing excess sample liquid 72 dripped onto the label pad 31 and directing the sample liquid 72 to the inner bottom surface 12A of the case body 12. In the examples shown in FIGS. 7 to 9 , the first absorbent body 21 is not in contact with the inner bottom surface 12A and is supported by a support portion (not shown). However, as shown in FIG. 10 , the first absorbent body 21 may be in contact with the inner bottom surface 12A of the case body 12. FIG. 10 is a cross-sectional view similar to FIG. 9 and shows a modified example of the first absorbent body 21. When the first absorbent body 21 is in contact with the inner bottom surface 12A of the case body 12, the sample liquid 72 absorbed by the first absorbent body 21 can be directed to the inner bottom surface 12A.

[0098] 10 , a sealing member 23 made of an adhesive or the like is preferably provided between the first absorbent body 21 and the carrier 30 and back adhesive sheet 34 of the test strip 14. In the example shown in FIG. 10 , the sealing member 23 limits the contact area between the first absorbent body 21 and the test strip 14 to only the label pad 31. The sealing member 23 may be any member that prevents the sample liquid 72 from passing back and forth between the first absorbent body 21 and the carrier 30 and back adhesive sheet 34. The sealing member 23 may be an adhesive or a liquid-impermeable member such as a resin film.

[0099] If the only contact area between the first absorbent body 21 and the test strip 14 is the labeled pad 31, when the sample liquid 72 in the first absorbent body 21 is returned to the test strip 14, it will always pass through the labeled pad 31, thereby ensuring contact between the sample liquid 72 and the labeled substance 70.

[0100] Modified examples of the first absorbent body and the second absorbent body will be described below with reference to Figures 11 to 15. Figures 11 to 14 (a) and (b) correspond to Figures 8 (a) and 8 (b), respectively, and are plan views and cross-sectional views of the periphery of the sign pad 31. Figures 15 (a) and (b) are plan views of the periphery of the sign pad 31 corresponding to Figure 8 (a), and (b) is a cross-sectional view taken along the line b-b in Figure 15 (a).

[0101] 11 , the first absorbent body 121 is disposed at a distance from the inner bottom surface 12A of the case body 12, and the second absorbent body 122 is disposed directly below the first absorbent body 121. As indicated by arrow 88 in FIG. 11 , the sample liquid 72 absorbed by the first absorbent body 121 leaks out from the lower end 121a of the first absorbent body 121 due to its own weight and is absorbed by the second absorbent body 122 disposed directly below the first absorbent body 121. This configuration prevents the sample liquid 72 from spreading onto the inner bottom surface 12A of the case body 12, allowing the sample liquid 72 to be efficiently absorbed by the second absorbent body 122.

[0102] In the example shown in Figure 12, the first absorber 131 is arranged so that its lower end 131a contacts the inner bottom surface 12A of the case body 12. Furthermore, two absorbers 132A and 132B (hereinafter referred to as second absorbers 132A and 132B) are arranged as the second absorber 132, one upstream and one downstream of the first absorber 131. The sample liquid 72 absorbed by the first absorber 131 moves vertically downward within the first absorber 131 due to capillary force and / or its own weight, as shown by arrow 86 in Figure 12(b). The sample liquid 72 leaking from the lower end 131a of the first absorber 131 and spreading onto the inner bottom surface 12A of the case body 12 may spread both upstream and downstream.

[0103] Since the second absorbents 132A and 132B are arranged on the upstream and downstream sides, respectively, the sample liquid 72 leaking onto the inner bottom surface 12A can be absorbed by the second absorbents 132A and 132B on the upstream and downstream sides, as shown by arrows 87A and 87B in Figure 12 (b).

[0104] In this way, if the second absorbent body 132 is composed of multiple absorbents 132A, 132B arranged around the first absorbent body 131, excess sample liquid 72 leaking from the first absorbent body 131 can be absorbed quickly and with high accuracy.

[0105] In the above example, the second absorber 132 is composed of two absorbers 132A and 132B, but the second absorber 132 may be composed of three or more absorbers. The arrangement of the multiple absorbers 132A and 132B is not limited to the upstream and downstream sides, and they may be arranged in parallel with the first absorber 131 in the X direction of the first absorber 131.

[0106] In the example shown in Fig. 13, the first absorber 131 is the same as that shown in Fig. 12. The second absorber 142 has one side with a length Ld that is equal to or greater than the length Lc of the first absorber 131 along the longitudinal direction (Y direction in Fig. 13) of the test strip 14. The second absorber 142 is disposed in such a manner that the direction of the length Ld, i.e., the side with the length Ld, is aligned with the longitudinal direction of the test strip 14, and the surface having the side with the length Ld faces the first absorber 131.

[0107] If the second absorbent body 142 has a length Ld equal to or greater than the length Lc of the first absorbent body 131 and is positioned opposite the first absorbent body 131, it can quickly absorb excess sample liquid 72 that leaks from the first absorbent body 131.

[0108] In the example shown in FIG. 14, the first absorber 131 is the same as that shown in FIGS.

[0109] The second absorber 152 has a shape that surrounds the periphery of the first absorber 131. In this example, the second absorber 152 is U-shaped. Note that the "surrounding shape" here refers to a shape in which the second absorber 152 has portions that face at least two surfaces of the first absorber 131. Therefore, the second absorber 152 is not limited to a U-shape, and may be an L-shape or a shape that surrounds the first absorber 131 in a ring shape.

[0110] In this way, if the second absorbent body 152 has a shape that surrounds the first absorbent body 131, the excess sample liquid 72 that leaks from the first absorbent body 131 can be absorbed quickly and with high accuracy.

[0111] 15 , the first absorber 161 is made up of two absorbers 161A and 161B (hereinafter referred to as the first absorber 161A and the first absorber 161B), and the second absorber 162 is made up of two absorbers 162A and 162B (hereinafter referred to as the second absorber 162A and the second absorber 162B). As shown in Fig. 15 , the first absorber 161A and the first absorber 161B are arranged on either side of the test strip 14, and the second absorber 162A and the second absorber 162B are arranged on either side of the test strip 14. The first absorber 161A and the first absorber 161B are arranged in the same shape and orientation as the first absorber 131 shown in Fig. 12 . The second absorbent body 162A and the second absorbent body 162B are arranged in the same shape and posture as the U-shaped second absorbent body 152 shown in FIG.

[0112] In this way, if the first absorbers 161A, 161B and the second absorbers 162A, 162B are arranged to sandwich the test strip 14, excess sample liquid 72 can be absorbed from both sides in the width direction of the label pad 31. Furthermore, since the sample liquid 72 absorbed by the first absorbers 161A and 161B is returned to the label pad 31 from both sides in the width direction, the sample liquid 72 can pass through both sides of the label pad 31 evenly compared to when the first absorbers 161A and 161B are arranged on only one side of the label pad 31, and the reaction between the analyte 73 and the labeling substance 70 can be promoted.

[0113] The above-described description and illustrations are a detailed explanation of the parts related to the technology of the present disclosure and are merely an example of the technology of the present disclosure. For example, the above description of the configuration, functions, actions, and effects is an explanation of an example of the configuration, functions, actions, and effects of the parts related to the technology of the present disclosure. Therefore, it goes without saying that unnecessary parts may be deleted, new elements may be added, or replacements may be made to the above-described description and illustrations within the scope of the gist of the technology of the present disclosure. Furthermore, to avoid confusion and facilitate understanding of the parts related to the technology of the present disclosure, the above-described description and illustrations omit explanations of common technical knowledge that do not require particular explanation to enable the implementation of the technology of the present disclosure.

[0114] The disclosure of Japanese Patent Application No. 2023-119417, filed on July 21, 2023, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

[0115] The following additional notes are further disclosed regarding the above embodiment. <Supplementary Note 1> An immunochromatographic testing device comprising: a test strip having a test area in which sample liquid is developed and a test substance contained in the sample liquid is captured, the test strip having a labeled pad upstream of the test area containing a labeled substance that labels the test substance; a case for accommodating the test strip, the case comprising: a cover member having a drip port for dripping sample liquid onto the labeled pad of the test strip; and a case body having a recess for accommodating the test strip, the case body having a support base on the inner bottom surface of the recess that supports the test strip above the inner bottom surface; a first absorbent body arranged laterally in the width direction of the test strip, in contact with at least a side surface of the labeled pad and extending towards the inner bottom surface of the case body, the first absorbent body absorbing the sample liquid by capillary force; and a second absorbent body arranged on the inner bottom surface of the case body at a position spaced apart from the test strip and the first absorbent body, the second absorbent body absorbing sample liquid leaking from the first absorbent body.

[0116] <Supplementary Note 2> The immunochromatographic testing device according to Supplementary Note 1, wherein the amount of liquid that can be held by the first absorbent body is equal to or less than a specified amount to be dropped onto the test strip.

[0117] <Supplementary Note 3> The immunochromatographic testing device according to Supplementary Note 1 or Supplementary Note 2, wherein the total amount of liquid that can be held by the labeling pad and the first absorbent body is 1 to 2 times the specified amount to be dropped onto the test strip.

[0118] <Supplementary Note 4> The immunochromatographic testing device according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the first absorbent body is made of the same material as the material of the labeling pad.

[0119] <Supplementary Note 5> The immunochromatographic test device according to any one of Supplementary Note 1 to Supplementary Note 4, wherein the only contact area between the first absorbent body and the test strip is the label pad.

[0120] <Supplementary Note 6> The immunochromatographic testing device according to any one of Supplementary Note 1 to Supplementary Note 5, wherein the first absorber contains a labeling substance.

[0121] <Supplementary Note 7> The immunochromatographic testing device according to any one of Supplementary Note 1 to Supplementary Note 6, wherein the second absorbent body is composed of a plurality of absorbent bodies arranged around the first absorbent body.

[0122] <Appendix 8> The immunochromatographic testing device according to any one of Appendices 1 to 7, wherein the second absorbent body has a length equal to or greater than the length of the first absorbent body along the longitudinal direction of the test strip, and is disposed so as to be aligned longitudinally with and opposite the first absorbent body.

[0123] <Supplementary Note 9> The immunochromatographic test device according to any one of Supplementary Note 1 to Supplementary Note 8, wherein the first absorber is in contact with the inner bottom surface of the case main body.

[0124] <Supplementary Note 10> The immunochromatographic testing device according to any one of Supplementary Note 1 to Supplementary Note 8, wherein the first absorbent body is disposed apart from the inner bottom surface of the case body, and the second absorbent body is disposed directly below the first absorbent body.

[0125] <Supplementary Note 11> The immunochromatographic testing device according to any one of Supplementary Note 1 to Supplementary Note 9, wherein the second absorber has a shape that surrounds the periphery of the first absorber.

[0126] <Supplementary Note 12> The immunochromatographic testing device according to any one of Supplementary Note 1 to Supplementary Note 11, wherein the second absorber is disposed at a position at a distance of 1 mm or less from the first absorber.

[0127] <Supplementary Note 13> The immunochromatographic testing device according to any one of Supplementary Note 1 to Supplementary Note 12, wherein the first absorbent body and the second absorbent body are disposed on both sides of the test strip.

Claims

1. A test strip having a test area in which a sample liquid is developed and a test substance contained in the sample liquid is captured, the test strip having a labeling pad upstream of the test area containing a labeling substance that labels the test substance; a case for housing the test strip, the case comprising: a cover member having a drip port for dripping the sample liquid onto the labeling pad of the test strip; and a case body having a recess for housing the test strip, the case body having a support base on the inner bottom surface of the recess that supports the test strip above the inner bottom surface; a first absorbent body arranged laterally in the width direction of the test strip, in contact with at least a side surface of the labeling pad and extending toward the inner bottom surface of the case body, the first absorbent body absorbing the sample liquid by capillary force; and a second absorbent body arranged on the inner bottom surface of the case body at a position spaced apart from the test strip and the first absorbent body, the second absorbent body absorbing the sample liquid leaking out of the first absorbent body. An immunochromatographic testing device comprising:

2. The immunochromatographic testing device according to claim 1, wherein the amount of liquid that can be held by the first absorbent body is equal to or less than a specified amount to be dropped onto the test strip.

3. The immunochromatographic testing device according to claim 1, wherein the total amount of liquid that can be held by said label pad and said first absorbent body is 1 to 2 times the specified amount to be dropped onto said test strip.

4. The immunochromatographic testing device according to claim 1, wherein the first absorbent body is made of the same material as the label pad.

5. An immunochromatographic testing device according to any one of claims 1 to 4, wherein the only contact area between the first absorbent body and the test strip is the label pad.

6. The immunochromatographic testing device according to any one of claims 1 to 4, wherein the first absorbent contains the labeling substance.

7. An immunochromatographic testing device according to any one of claims 1 to 4, wherein the second absorbent body is composed of a plurality of absorbents arranged around the first absorbent body.

8. An immunochromatographic testing device as described in any one of claims 1 to 4, wherein the second absorbent has a length equal to or greater than the length of the first absorbent along the longitudinal direction of the test strip, and is arranged in the longitudinal direction along the longitudinal direction and opposite the first absorbent.

9. An immunochromatographic testing device according to any one of claims 1 to 4, wherein the first absorbent body is in contact with the inner bottom surface of the case body.

10. An immunochromatographic testing device as described in any one of claims 1 to 4, wherein the first absorbent body is positioned at a distance from the inner bottom surface of the case body, and the second absorbent body is positioned directly below the first absorbent body.

11. An immunochromatographic testing device according to any one of claims 1 to 4, wherein the second absorbent body is shaped to surround the periphery of the first absorbent body.

12. An immunochromatographic testing device according to any one of claims 1 to 4, wherein the second absorbent body is disposed at a distance of 1 mm or less from the first absorbent body.

13. An immunochromatographic testing device according to any one of claims 1 to 4, wherein the first absorbent body and the second absorbent body are arranged on either side of the test strip.

Images