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

Patent metadata

Field	Value
Publication number	US-10151747-B2
Application number	US-201615389015-A
Country	US
Kind code	B2
Filing date	Dec 22, 2016
Priority date	Mar 30, 2012
Publication date	Dec 11, 2018
Grant date	Dec 11, 2018

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 inventers 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 inventers 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 detection method, comprising the steps of:
(A) supplying a sample to a sample-supply portion of a test strip, said test strip comprising a membrane, said 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, and
wherein a conjugate comprising a colloidal gold sensitized with an anti-analyte antibody 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;
(B) agglutinating red blood cells in the sample through contact between hexadimethrine bromide and the sample in the sample-supply portion or in the upstream of the sample-supply portion;
(C) separating and removing aggregates acquired at step (B) from the sample;
(D) bringing a sample component acquired at step (C) after separation and removal of the aggregates into contact with the colloidal gold-containing conjugate, the step being performed in the presence of a buffer solution component; and
(E) detecting a complex of the analyte in the sample component and the conjugate acquired at the step (D) in the detecting part, and
wherein the buffer solution component is selected from the group consisting of Bis-Tris, MES, and citric acid.

2. The detection method of claim 1 , wherein the sample-supply portion comprises hexadimethrine bromide.

3. The detection method of claim 1 , wherein the sample-supply portion contains the buffer solution component for suppressing aggregation of the conjugate due to hexadimethrine bromide.

4. The detection method of claim 2 , wherein the sample-supply portion contains the buffer solution component for suppressing aggregation of the conjugate due to hexadimethrine bromide.

5. The detection method of claim 1 , wherein the test strip does not comprise a polyanion as a neutralizer for neutralizing a cation of hexadimethrine bromide acting as the blood-agglutinating agent.

6. The detection method of claim 1 , wherein the buffer solution component is Bis-Tris.

7. The detection method of claim 1 , wherein the buffer solution component is MES.

8. The detection method of claim 1 , wherein the buffer solution component is citric acid.

9. The detection method of claim 1 , wherein the sample-supply portion comprises glass fiber.

Assignees

• Sekisui Medical Co Ltd

Inventors

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

Classifications

• G01N33/54366

  Apparatus specially adapted for solid-phase testing · 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

• 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

• G01N33/5306 Primary

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