ASSAY UTILIZING IMMUNOCHROMATOGRAPHY, IMMUNOCHROMATOGRAPHIC TEST STRIP, AND ASSAY REAGENT KIT FOR IMMUNOCHROMATOGRAPHY

• US 20130052655A1
• Filed: 03/31/2011
• Published: 02/28/2013
• Est. Priority Date: 03/31/2010
• Status: Active Grant

• Current Assignee: Sekisui Medical Company Limited (Sekisui)
• Original Assignee: Sekisui Medical Company Limited (Sekisui)
• Inventors: Ito, Sachiko, Kobayashi, Koji, Morita, Motoki
• Granted Patent: US 9,903,865 B2
• Time in Patent Office: Days
• US Class Current: 435/7.1
• CPC Class Codes: G01N 2333/4737 C-reactive protein
• CPC Class Codes: G01N 2333/805 Haemoglobins; Myoglobins
• CPC Class Codes: G01N 33/54388 based on lateral flow
• CPC Class Codes: G01N 33/558 using diffusion or migration of antigen or antibody immunochromatographic test strips G01N33/54387
• CPC Class Codes: G01N 33/721 Haemoglobin

Abstract

The present invention provides a measurement method utilizing immunochromatography, an immunochromatographic test strip, and a reagent kit of immunochromatography capable of accurate short-time measurement of an analyte in blood with simple operations as compared to the conventional methods. The present invention provides a method of measurement by immunochromatography in which concentrations of an analyte and hemoglobin in the same sample are measured by immunochromatography to perform hematocrit correction of a measurement value of the analyte by using a measurement value of hemoglobin, as well as a test strip and a reagent kit for immunochromatography.

Claims

1. A method of measuring a sample containing at least a first analyte by immunochromatography including the following step A, wherein

a concentration of the first analyte in the sample is measured in a concentration range (prozone phenomenon region) equal to or greater than a concentration at which the maximum signal value of the first analyte is acquired,

A. a step of measuring the first analyte in the sample by competitive immunochromatography using 1) and 2) described below:

1) a conjugate in which a first antibody against the first analyte is immobilized to a label; and

2) an insoluble membrane support to which a second antibody against the first analyte is immobilized (if an epitope of the first antibody against the first analyte is monovalent, an epitope of the second antibody is different from the first antibody, while if an epitope of the first antibody is multivalent, an epitope of the second antibody may be the same as the first antibody or the first antibody may be the same as the second antibody in some cases).

2. The method of claim 1, wherein the step A further uses 3) and 4) described below and wherein the conjugate of 1) is contained in a pad to form a conjugate pad and disposed on the upstream side of the insoluble membrane support of 2),a sample pad located on the upstream side of the conjugate pad and supplied with the sample, andan absorbent pad located on the downstream side of the insoluble membrane support of 2).

3. The method of claim 1 or 2, wherein the first analyte is hemoglobin, and wherein the sample is acquired by diluting and hemolyzing blood into a concentration range (prozone phenomenon region) equal to or greater than a concentration at which the maximum signal value of hemoglobin measurement is acquired.

4. A method of measuring a sample containing at least hemoglobin as a first analyte and a second analyte by immunochromatography including the following steps A to D:

A. a step of measuring the first analyte in the sample by competitive immunochromatography using

     1) and

     2) described below,

1) a conjugate in which a first antibody against the first analyte is immobilized to a label, and

2) an insoluble membrane support to which a second antibody against the first analyte is immobilized (if an epitope of the first antibody against the first analyte is monovalent, an epitope of the second antibody is different from the first antibody, while if an epitope of the first antibody is multivalent, an epitope of the second antibody may be the same as the first antibody or the first antibody may be the same as the second antibody in some cases);

B. a step of measuring the second analyte in the sample by immunochromatography using

     5) and

     6) described below,

5) a conjugate in which a first antibody against the second analyte is immobilized to a label, and

6) an insoluble membrane support which a second antibody against the second analyte is immobilized to (if an epitope of the first antibody against the second analyte is monovalent, an epitope of the second antibody is different from the first antibody, while if an epitope of the first antibody is multivalent, an epitope of the second antibody may be the same as the first antibody or the first antibody may be the same as the second antibody in some cases);

C. a step of obtaining a hematocrit value of the sample from a measurement value of the first analyte acquired at the step A; and

D. a step of correcting a measurement value of the second analyte acquired at the step B by using the hematocrit value acquired at the step C.

5. The method of claim 4, wherein the steps A and B are steps using the same insoluble membrane support.

6. The method of claim 5, wherein the steps A and B are performed in the same flow passage.

7. The method of any one of claims 4 to 6, wherein the second analyte is C-reactive protein (CRP).

8. An immunochromatographic test strip for measuring a sample containing at least a first analyte and a second analyte by immunochromatography, the immunochromatographic test strip comprising the following E and F:

E. a test strip for measuring the first analyte including

     1) and

     2) described below,

1) a conjugate in which a first antibody against the first analyte is immobilized to a label, and

2) an insoluble membrane support to which a second antibody against the first analyte is immobilized (if an epitope of the first antibody against the first analyte is monovalent, an epitope of the second antibody is different from the first antibody, while if an epitope of the first antibody is multivalent, an epitope of the second antibody may be the same as the first antibody or the first antibody may be the same as the second antibody in some cases); and

F. a test strip for measuring the second analyte including

     5) and

     6) described below,

5) a conjugate in which a first antibody against the second analyte is immobilized to a label, and

6) an insoluble membrane support which a second antibody against the second analyte is immobilized to (if an epitope of the first antibody against the second analyte is monovalent, an epitope of the second antibody is different from the first antibody, while if an epitope of the first antibody is multivalent, an epitope of the second antibody may be the same as the first antibody or the first antibody may be the same as the second antibody in some cases).

9. The immunochromatographic test strip of claim 8, wherein the conjugates of 1) of E and 5) of F are contained in the same pad to form a conjugate pad, and wherein the insoluble membrane support of 2) of E is the same as the insoluble membrane support of 6) of F.

10. The immunochromatographic test strip of claim 9, wherein E and F are disposed in the same flow passage.

11. The immunochromatographic test strip of any one of claims 8 to 10, further comprising the following G and H, wherein the conjugates of 1) of E and 5) of F are contained in a pad to form a conjugate pad and disposed on the upstream side of the insoluble membrane support of 2) of E and 6) of F,

G. a sample pad located on the upstream side of the conjugate pad and supplied with a sample, and

H. an absorbent pad located on the downstream side of the insoluble membrane support of 2) of E and 6) of F.

12. The immunochromatographic test strip of claim 8, wherein the first analyte is hemoglobin.

13. The immunochromatographic test strip of claim 12, wherein the second analyte is C-reactive protein (CRP).

14. An assay reagent kit for immunochromatography comprising:

the immunochromatographic test strip of claim 12 or 13; and

a diluting solution for hemolysis and dilution.

15. A method of measuring a sample containing at least a first analyte and a second analyte by immunochromatography including the following steps A and B:

A. a step of measuring the first analyte in the sample by competitive immunochromatography using

     1) and

     2) described below,

1) a conjugate in which a first antibody against the first analyte is immobilized to a label, and

2) an insoluble membrane support to which a second antibody against the first analyte is immobilized (if an epitope of the first antibody against the first analyte is monovalent, an epitope of the second antibody is different from the first antibody, while if an epitope of the first antibody is multivalent, an epitope of the second antibody may be the same as the first antibody or the first antibody may be the same as the second antibody in some cases); and

B. a step of measuring the second analyte in the sample by immunochromatography using

     5) and

     6) described below,

5) a conjugate in which a first antibody against the second analyte is immobilized to a label, and

6) the insoluble membrane support same as

     2) of A which a second antibody against the second analyte is immobilized to (if an epitope of the first antibody against the second analyte is monovalent, an epitope of the second antibody is different from the first antibody, while if an epitope of the first antibody is multivalent, an epitope of the second antibody may be the same as the first antibody or the first antibody may be the same as the second antibody in some cases).

16. The method of claim 15, wherein the second analyte is C-reactive protein (CRP).