Reagent containing protease reaction promoter and/or colorant stabilizer

• US 8,080,423 B2
• Filed: 08/04/2005
• Issued: 12/20/2011
• Est. Priority Date: 08/05/2004
• Status: Active Grant

• Current Assignee: Asahi Kasei Pharma Corporation (Asahi Kasei Corporation)
• Original Assignee: Asahi Kasei Pharma Corporation (Asahi Kasei Corporation)
• Inventors: Kouzuma, Takuji, Imamura, Shigeyuki, Nagai, Yoko
• Primary Examiner(s): Wallenhorst, Maureen
• Application Number:
  US11/573,179
• Publication Number:
  US 20070224685A1
• Time in Patent Office: 2,329 Days
• Field of Search: 436/8, 436/18, 436/63, 436/66, 436/67, 436/164, 436/166, 436/174, 436/176, 436/86, 436/88, 435/23, 435/27, 435/28, 435/24, 435/189, 435/195, 252/408.1, 536/103
• US Class Current: 436/67
• CPC Class Codes: C12N 9/96 Stabilising an enzyme by forming an adduct or a composition; Forming enzyme conjugates
• CPC Class Codes: C12Q 1/37 involving peptidase or proteinase
• CPC Class Codes: G01N 2333/95 Proteinases, i.e. endopeptidases (3.4.21-3.4.99)
• CPC Class Codes: G01N 2333/964 derived from animal tissue
• CPC Class Codes: G01N 33/723 Glycosylated haemoglobin
• CPC Class Codes: Y10T 436/108331 Preservative, buffer, anticoagulant or diluent
• CPC Class Codes: Y10T 436/25 including sample preparation
• CPC Class Codes: Y10T 436/2525 Stabilizing or preserving

Abstract

Stabilizers for colorants used for detection of enzymatic reactions, having a cyclodextrin and a catalase; reagents including stabilizers; and methods of use of such stabilizers and reagents.

Claims

1. A method for stabilizing a kit of compositions comprising a first composition and a second composition used for the measurement of glycated hemoglobin or glycated albumin in a sample comprising:

making a protease, 10-(carboxymethylaminocarbonyl)-3,7-bis(dimethylamino)phenothiazine, and a cyclodextrin coexist together in the absence of a sample containing glycated hemoglobin or glycated albumin, and thereby providing the first composition comprising the protease, 10-(carboxymethylaminocarbonyl)-3,7-bis(dimethylamino)phenothiazine, and the cyclodextrin with no sample containing glycated hemoglobin or glycated albumin, and

providing the second composition containing an oxidase which oxidizes a glycated amino acid and/or a glycated peptide,

wherein the first and second compositions of the kit remain stable in a liquid state for 6 months or longer under refrigeration in the absence of a sample containing glycated hemoglobin or glycated albumin.

2. The method according to claim 1, wherein the cyclodextrin is a β

-cyclodextrin.

3. The method according to claim 1, wherein the first composition containing the protease, 10-(carboxymethylaminocarbonyl)-3,7-bis(dimethylamino)phenothiazine, and the cyclodextrin further comprises a buffer in a concentration of 100 mM or less.

4. The method according to claim 3, wherein the first composition containing the protease, 10-(carboxymethylaminocarbonyl)-3,7-bis(dimethylamino)phenothiazine, and the cyclodextrin further comprises a buffer in a concentration of 80 mM or less.

5. A method of measuring glycated hemoglobin or glycated albumin in a blood sample, comprising:

adding to the blood sample,

the first composition stabilized by the method according to claim 1, thus providing a mixture of the blood sample and the first composition,

adding to the mixture the second composition according to claim 1, and

detecting through the activity of the oxidase which oxidizes a glycated amino acid and/or a glycated peptide, the presence of glycated amino acids and/or glycated peptides cleaved from glycated hemoglobin or glycated albumin present in the blood sample.

6. The method according to claim 5, wherein the cyclodextrin is a β

-cyclodextrin.

7. The method according to claim 5, wherein the first composition containing the protease, 10-(carboxymethylaminocarbonyl)-3,7-bis(dimethylamino)phenothiazine, and the cyclodextrin further comprises a buffer in a concentration of 100 mM or less.

8. The method according to claim 7, wherein the first composition containing the protease, 10-(carboxymethylaminocarbonyl)-3,7-bis(dimethylamino)phenothiazine, and the cyclodextrin further comprises a buffer in a concentration of 80 mM or less.