Kit for assaying saccharified protein

• US 20030226769A1
• Filed: 02/04/2003
• Published: 12/11/2003
• Est. Priority Date: 05/23/2000
• Status: Abandoned Application

• Current Assignee: Koji Sode
• Original Assignee: Koji Sode
• Inventors: Sode, Koji
• Application Number:
  US10/296,323
• Publication Number:
  US 20030226769A1
• Time in Patent Office: Days
• US Class Current: 205/777.5
• CPC Class Codes: G01N 2400/00 Assays, e.g. immunoassays or enzyme assays, involving carbohydrates
• CPC Class Codes: G01N 33/66 involving blood sugars, e.g. galactose
• CPC Class Codes: G01N 33/723 Glycosylated haemoglobin

Abstract

A novel method of assaying glycated hemoglobin, glycated albumin or a fructosamine which is a degradation product thereof are disclosed. In particular, the present invention provides a method for assaying fructosamine which comprises oxidizing fructosamine by using a compound having an imidazole group as a catalyst in the presence of an appropriate mediator (an electron acceptor), and measuring the reduced form of the mediator.

Claims

1. A method for assaying fructosamine comprising oxidizing fructosamine in the presence of an appropriate mediator (electron acceptor) and an imidazole containing compound as a catalyst, and measuring the amount of the reduced mediator.

4. The method according to any one of claims 1 to 3 wherein the imidazole-containing compound is a polymer of vinylimidazole.

5. The method according to any one of claims 1 to 3 wherein the amount of the reduced mediator formed by the reaction between fructosamine and the imidazole containing compound is measured by spectroscopy.

6. The method according to any one of claims 1 to 3 wherein the amount of the reduced mediator formed by the reaction between the fructosamine and the imidazole containing compound is measured electrochemically.

16. A method for diagnosis of diabetes mellitus comprising the step of measuring fructosamine or a glycated protein in a sample from a subject using the method as claimed in any one of claims 1 to 3.

2. A method for assaying fructosamine in a sample comprising the steps of:

1) reacting the sample in a reaction solution at pH 6-10 with an imidazole containing compound in the presence of a mediator;

2) measuring the amount of a reduced mediator formed by the reaction; and

3) determining the concentration of the fructosamine in the sample based on a calibration curve prepared by using standard fructosamine solutions.

3. A method for assaying a glycated protein in a sample comprising the steps of:

1) enzymatically or chemically degrading the glycated protein in the sample to form fructosamine;

2) reacting the sample in a reaction solution at pH 6-10 with an imidazole containing compound in the presence of a mediator;

3) measuring the amount of a reduced mediator formed by the reaction;

4) determining the concentration of the fructosamine based on a calibration curve prepared by using standard fructosamine solutions; and

5) determining the amount of the glycated protein in the sample based on the concentration of the fructosamine.

7. The method according to claim 3 wherein the glycated protein is glycated hemoglobin or glycated albumin.

8. A fructosamine assay kit comprising an imidazole containing compound, which may optionally comprise at least one selected from a buffer solution, a mediator, a standard solution of a fructosamine or its derivative for the preparation of a calibration curve, and a direction for use.

9. A sensor for fructosamine assay, comprising a working electrode on which an imidazole containing compound is immobilized, a counter electrode, and a reference electrode in a buffer solution.

10. The sensor for fructosamine assay according to claim 9 wherein the buffer solution comprises a mediator.

11. The sensor for fructosamine assay according to claim 9 or 10 wherein the electrode comprises carbon paste.

12. A glycated hemoglobin assay kit comprising an imidazole containing compound, which may optionally comprise at least one selected from a hydrolytic reagent or proteolytic enzyme capable of acting on glycated hemoglobin, a buffer solution, a mediator, a standard solution of fructosyl-valine or its derivative for the preparation of a calibration curve, and a direction for use.

13. A sensor for glycated hemoglobin assay comprising a working electrode on which an imidazole containing compound is immobilized, a counter electrode, and a reference electrode in a buffer solution.

14. A glycated albumin assay kit comprising an imidazole containing compound, which may optionally comprise at least one selected from a hydrolytic reagent or proteolytic enzyme capable of acting on glycated albumin, a buffer solution, a mediator, a standard solution of fructosyl-E-lysine or its derivative for the preparation of a calibration curve, and a direction for use.

15. A sensor for glycated albumin assay comprising a working electrode on which an imidazole containing compound is immobilized, a counter electrode, and a reference electrode in a buffer solution.