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EP-4242657-B1 - IMMUNOCHROMATOGRAPHY ASSAY KIT

EP4242657B1EP 4242657 B1EP4242657 B1EP 4242657B1EP-4242657-B1

Inventors

  • HARIYAMA, Takahiko
  • KAWASAKI, HIDEYA
  • OHBA, HIROAKI

Dates

Publication Date
20260513
Application Date
20211102

Claims (11)

  1. An immunochromatography assay kit (100, 101, 102, 103) comprising: a specimen dropping portion (1) to which a specimen is dropped; a conjugate portion (2) to which a labeled antibody having a property of binding to a detection target in the specimen is attached; and a detection region (t) including at least one detection portion (3) to which a capture antibody having a property of binding to the detection target is attached, wherein the specimen dropping portion (1), the conjugate portion (2), and the at least one detection portion (3) are formed on a porous member (6), at least one recess (7) is formed in the detection region (t) of the porous member (6) and is recessed with respect to an upper surface of the porous member (6), the at least one recess (7) has a bottom surface (7A) and a wall surface (7B) connecting the bottom surface (7A) and the upper surface of the porous member (6), the bottom surface (7A) having a dot shape and a sectional shape of the recess (7) having a tapered shape, and the capture antibody is immobilized on the bottom surface (7A) of the at least one recess (7).
  2. The immunochromatography assay kit according to claim 1, wherein a width of the at least one detection portion (3) is less than 1 mm.
  3. The immunochromatography assay kit according to claim 1 or 2, wherein the width of the at least one detection portion (3) is less than or equal to 100 µm.
  4. The immunochromatography assay kit according to any one of claims 1 to 3, wherein the at least one detection portion (3) is a plurality of detection portions (3).
  5. The immunochromatography assay kit according to any one of claims 1 to 4, wherein the at least one detection portion (3) is a plurality of detection portions (3), the at least one recess (7) is a plurality of recesses (7), and each of the plurality of detection portions (3) includes a bottom surface (7A) of one of the plurality of recesses (7).
  6. The immunochromatography assay kit according to claim 4 or 5, wherein the plurality of detection portions (3) are arranged one-dimensionally or two-dimensionally.
  7. The immunochromatography assay kit according to any one of claims 4 to 6, wherein a shortest distance between two adjacent detection portions (3) among the plurality of detection portions (3) is less than 1 mm.
  8. The immunochromatography assay kit according to any one of claims 4 to 7, wherein the plurality of detection portions (3) include a first detection portion (3A) to which a first capture antibody having a property of binding to the detection target of a first type is immobilized and a second detection portion (3B) to which a second capture antibody having a property of binding to the detection target of a second type is immobilized.
  9. The immunochromatography assay kit according to any one of claims 1 to 8, wherein the specimen dropping portion (1), the conjugate portion (2), and the at least one detection portion (3) are formed on a single porous member (6).
  10. The immunochromatography assay kit according to any one of claims 1 to 8, wherein the specimen dropping portion (1), the conjugate portion (2), and the at least one detection portion (3) are formed on a plurality of the porous members (6).
  11. The immunochromatography assay kit according to any one of claims 1 to 10, wherein a planar outer shape of the bottom surface is a dot shape.

Description

TECHNICAL FIELD The present invention relates to an immunochromatography assay kit. BACKGROUND ART Immunochromatography is currently implemented in society as a diagnostic aid for various diseases with influenza viruses as a center. A principle of the immunochromatography uses an antigen-antibody reaction, and is widely used in medical practice due to simplicity and effectiveness. In the conventional immunochromatography, presence or absence of color development in a detection portion of an immunochromatography assay kit (also referred to as development support or chromatographic medium) is visually observed. Specifically, when a detection target bound to a labeled antibody is captured by a capture antibody immobilized on the detection portion and sufficiently accumulated on the detection portion, the color development derived from the labeled antibody is visually checked. WO 2010/061772 A1 (PTL 1) discloses an immunochromatography assay kit in which the detection portion is formed in a size greater than or equal to several mm that can be visually determined. EP 2 352 028 A1 discloses an immunochromatographic medium and an immunochromatographic method both of which, even when colors that can be detected by colored latex particles, i.e., more than four items, are to be detected, can detect and quantify the multiple items simultaneously. The immunochromatographic medium is characterized by comprising a support, a label-attached reagent which is immobilized on a labeling reagent and is arranged on the support, and a detection part on which a substance capable of binding to a substance to be detected in a sample is immobilized, wherein the labeling reagent is a fluorescent nano-particle and the detection part has a dot-like pattern. WO 2010/120951 A1, EP 2 554 992 A1 and IRINA V. SAFENKOVA ET AL, "Multiarray on a test strip (MATS): rapid multiplex immunodetection of priority potato pathogens", ANALYTICAL AND BIOANALYTICAL CHEMISTRY, Berlin/Heidelberg, (20160323), vol. 408, no. 22 disclose similar immunochromatographic test strips including circular detection areas. Further immunochromatographic test strips are known from PARK JAENAM ET AL, "Multiplex detection of pathogens using an immunochromatographic assay strip", BIOCHIP JOURNAL, Seoul , South Korea, vol. 4, no. 4, and from NADEZHDA A. TARANOVA ET AL, "Integration of lateral flow and microarray technologies for multiplex immunoassay: application to the determination of drugs of abuse", MIKROCHIMICA ACTA, (20130713), vol. 180, no. 11-12. In these strips, the upper surface of the porous member that defines the detection region is flat. In JP 2013/113633 A detection spots which are formed by protrusions. Further immunochromatographic test strips are known from CN 108 535 472 A, WO 2008/105814 A1 and THIBAULT C ET AL, "Direct microcontact printing of oligonucleotides for biochip applications", JOURNAL OF NANOBIOTECHNOLOGY, vol. 3, no. 1. CITATION LIST PATENT LITERATURE PTL 1: WO 2010/061772 A1 SUMMARY OF INVENTION TECHNICAL PROBLEM In the conventional immunochromatography assay kit as described in PTL 1, because the color development derived from the labeled antibody is visually checked, a sufficient area is required to be provided in order to prevent erroneous determination, and as a result, the area of the detection portion is greater than or equal to several mm2. For this reason, a large number of capture antibodies greater than or equal to some extent is required to be immobilized on the detection portion to capture the antigen, and it is difficult to reduce the amount of expensive capture antibodies used, and it is difficult to reduce the cost. A main object of the present invention is to provide a low-cost immunochromatography assay kit capable of suppressing the use amount of the capture antibody as compared with the conventional immunochromatography assay kit. SOLUTION TO PROBLEM An immunochromatography assay kit according to the present invention is defined in claim1. An immunochromatography assay kit according to an embodiment of the present invention includes a specimen dropping portion to which a specimen is dropped, a conjugate portion to which a labeled antibody having a property of binding to a detection target in the specimen is attached, and a detection region including at least one detection portion to which a capture antibody having a property of binding to a detection target is attached. The specimen dropping portion, the conjugate portion, and the at least one detection portion are formed on a porous member. At least one recess is formed in the detection region of the porous member. The at least one recess is recessed with respect to an upper surface of the porous member. The at least one recess has a bottom surface and a wall surface connecting the bottom surface and the upper surface of the porous member. The at least one recess member has a dot shape and a sectional shape of the recess has a tapered shape. The capture antibody is immobil