Immunochromatographic test strip and detection method using immunochromatography for detecting target in red blood cell-containing sample

Patent metadata

Field	Value
Publication number	US-10422790-B2
Application number	US-201715853503-A
Country	US
Kind code	B2
Filing date	Dec 22, 2017
Priority date	Mar 30, 2012
Publication date	Sep 24, 2019
Grant date	Sep 24, 2019

Abstract

A problem to be solved by the present invention is to provide an immunochromatographic test strip and a detection method using immunochromatography avoiding aggregation of colloidal gold conjugates while red blood cells in whole blood are agglutinated and then separated and removed in the case of using polybrene as a blood-agglutinating agent and the colloidal gold conjugates as a detection reagent. To solve the problem, the present inventors reviewed a past reagent configuration itself from a completely different viewpoint rather than selecting type and amount of polyanions and, as a result of extensive study on each element, the inventors surprisingly found that aggregation of colloidal gold can be suppressed by using a certain buffer solution without using neutralization by polyanions.

First claim

The invention claimed is:

1. An immunochromatographic test strip comprising:
(1) a membrane comprising a porous body, which comprises a sample-supply portion and a spreading portion,
wherein the sample-supply portion is upstream from the spreading portion,
wherein the sample-supply portion contains hexadimethrine bromide,
wherein a conjugate of an anti-analyte antibody labeled with colloidal gold is retained in a dissoluble manner in a conjugate-retaining part of the spreading portion, and an antibody is immobilized in a detecting part of the spreading portion, which is downstream from the conjugate-retaining part; and
(2) a buffer solution component in a dry state,
wherein the buffer solution component is contained in the conjugate-retaining part of the spreading portion so as to be able to contact with hexadimethrine bromide provided through the sample-supply portion, and
wherein the buffer solution component is selected from a group consisting of Bis-Tris, MES, and citric acid,
wherein the test strip does not comprise a polyanion as a neutralizer for neutralizing a cation of the hexadimethrine bromide.

2. The test strip of claim 1 , wherein the sample-supply portion contains the buffer solution component.

3. The test strip of claim 1 , wherein Bis-Tris and MES are at pH lower than pKa.

4. The test strip of claim 1 , wherein the conjugate-retaining part is a conjugate pad.

5. The test strip of claim 4 , wherein the sample-supply portion is a sample pad.

Assignees

• Sekisui Medical Co Ltd

Inventors

• Yoshida Mayumi
• Yamamoto Mitsuaki
• Yokokawa Shinya
• Shimizu Tomo
• Kono Keigo

Classifications

• B01L2300/0825

  Test strips · CPC title

• G01N33/54393 Primary

  Improving reaction conditions or stability, e.g. by coating or irradiation of surface, by reduction of non-specific binding, by promotion of specific binding · CPC title

• G01N33/5005

  involving human or animal cells (immunoassay G01N33/56966; immunoassays of protozoa G01N33/56905; protozoa in screening assays C12Q1/025) · CPC title

• G01N33/54366

  Apparatus specially adapted for solid-phase testing · CPC title

• G01N33/5306 Primary

  Improving reaction conditions, e.g. reduction of non-specific binding, promotion of specific binding · CPC title