Device and method for assay of liquid sample

• US 5,227,310 A
• Filed: 11/30/1989
• Issued: 07/13/1993
• Est. Priority Date: 12/01/1988
• Status: Expired due to Term

• Current Assignee: Kyoto Daiichi Kagaku Company Limited 57 Nishiaketa-Cho Higashikujo Minami-Ku Kyoto-Shi Kyoto-Fu Japan
• Original Assignee: Kyoto Daiichi Kagaku Company Limited
• Inventors: Sakamoto, Hisashi, Yamada, Shigeki, Taniguchi, Hiroshi
• Primary Examiner(s): Warden, Robert J.
• Assistant Examiner(s): McMahon, Timothy M.
• Application Number:
  US07/443,206
• Time in Patent Office: 1,321 Days
• Field of Search: 436/169, 436/170, 422/56, 422/57, 422/58, 435/14, 435/28, 435/805
• US Class Current: 436/169
• CPC Class Codes: G01N 33/525 Multi-layer analytical elements

Abstract

A device for colorimetric assay of at least one component in a liquid sample, which device comprises a support having a through hole with an area of from 3 to 80 mm², a transparent porous film which is provided on the support to cover the hole, a reagent layer provided on a surface of the porous film which is not contacted to the support, and a sample-holding layer which covers the reagent layer and a part of a surface of the support, whereby an amount or concentration of at least one component in the liquid sample may be easily and accurately measured.

Claims

1. A device for colorimetric assay of at least one component in a liquid sample, which device comprises a support having a first through hole with an area from 3 to 80 mm², a transparent porous air-permeable film which is provided on a surface of said support to cover said first through hole, a reagent layer having an inner surface and an outer surface, said inner surface being provided on a surface of said pours film which is not in contact with said support, said reagent layer containing an oxidase capable of oxidizing said at least one component, peroxidase and a pigment-precursor, and a sample-holding layer provided on aid outer surface of said reagent layer, such that said sample-holding layer covers at least a part of said reagent layer and a part of said support.

2. The device according to claim 1, wherein said porous film has a porosity of from 2 to 70%.

3. The device according to claim 1, wherein said porous film has a pore size of from 0.01 to 20 μ

m.

4. The device according to claim 1, wherein said porous film has a thickness of from 5 to 30 μ

m.

5. The device according to claim 1, wherein said reagent layer further contains light reflecting water-insoluble particles.

6. The device according to claim 1, wherein said support has a second through hole therein at a position which is covered only by said sample-holding layer.

7. The device according to claim 1, wherein said support comprises two support members having a single through hole which corresponds to each of a porous film side and sample-holding layer side of said device with respect to said reagent layer.

8. A process for analyzing at least one component in a liquid sample using the assay device of claim 1, which process comprises the steps of applying an amount of a liquid sample to said sample-holding layer such that said sample penetrates therein, and colorimetrically measuring a color developed in said reagent layer viewed through said first through hole of said support from the support side of said device.