Stabilized composition of tetrazolium salts

• US 4,613,569 A
• Filed: 03/27/1984
• Issued: 09/23/1986
• Est. Priority Date: 12/23/1980
• Status: Expired due to Fees

• Current Assignee: Boehringer Mannheim GmbH (Roche Holding AG)
• Original Assignee: Boehringer Mannheim GmbH (Roche Holding AG)
• Inventors: Lange, Hans, Geisler, Edda, Feuerstein, Helmut
• Primary Examiner(s): Kepplinger, Esther M.
• Application Number:
  US06/593,192
• Time in Patent Office: 910 Days
• Field of Search: 435/14, 435/25, 435/26, 435/27, 435/28, 435/4, 435/805, 435/810, 435/188, 436/93, 436/97, 436/903, 436/904, 436/176, 436/95, 422/56
• US Class Current: 435/26
• CPC Class Codes: C12Q 1/32 involving dehydrogenase
• CPC Class Codes: G01N 33/52 Use of compounds or compositions for colorimetric, spectrophotometric or fluorometric investigation, e.g. use of reagent paper and including single- and multilayer analytical elements immunological elements G01N33/54386; involving labelled immunochemicals G01N33/58; for haemoglobin or occult blood G01N33/72
• CPC Class Codes: Y10S 435/805 Test papers
• CPC Class Codes: Y10S 435/81 Packaged device or kit
• CPC Class Codes: Y10S 436/903 Diazo reactions
• CPC Class Codes: Y10T 436/142222 Hetero-O [e.g., ascorbic acid, etc.]
• CPC Class Codes: Y10T 436/144444 Glucose
• CPC Class Codes: Y10T 436/146666 Bile pigment
• CPC Class Codes: Y10T 436/201666 Carboxylic acid
• CPC Class Codes: Y10T 436/2525 Stabilizing or preserving

Abstract

The present invention provides stabilized compositions of tetrazolium salts for analytical purposes, wherein they contain 1 to 10 moles of a complex-forming acid which is soluble in polar solvents per mole of tetrazolium salt.

The present invention also provides a process for the detection of reducing materials, wherein one of the above stabilized compositions is added to a test batch.

Claims

1. Method for the detection of reducing materials by means of tetrazolium salts which method comprises adding a tetrazolium salt stabilized by the addition of 1 to 10 moles of a complex-forming acid selected from the group consisting of boric acid and an organic hydroxypolycarboxylic acid which is soluble in polar solvents, per mole of tetrazolium salts, to a solution buffered to the reaction conditions of the other reagents;

subsequently adding the sample thereto and measuring the color change.

2. Method as claimed in claim 1, further comprising adding diaphorase as an activator for the tetrazolium salts.

3. Method as claimed in claim 1, further comprising adding PMS as an activator for the tetrazolium salts.

4. The method as claimed in claim 1 wherein 1 to 2 moles of the complex-forming acid is used per mole of tetrazolium salt.

5. The method as claimed in claim 1, wherein the complex-forming acid is boric acid.

6. The method as claimed in claim 1, wherein said complex forming acid is an organic hydroxypolycarboxylic acid.

7. The method as claimed in claim 1, wherein the complex forming acid is citric acid.

8. The method as claimed in claim 1, wherein the tetrazolium salt is 3-(4'"'"',5'"'"'-dimethylthiazolyl-2)-2,4-diphenyltetrazolium bromide.

9. The method as claimed in claim 1, wherein the tetrazolium salt is 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyltetrazolium chloride.

10. The method as claimed in claim 1, wherein the tetrazolium salt is 2,2'"'"'-di-(p-nitrophenyl)-5,5'"'"'-diphenyl-3,3'"'"'-(3,3'"'"'-dimethoxy-4,4'"'"'-diphenylene)-ditetrazolium chloride.

11. The method as claimed in claim 1, wherein the stabilized composition is in the form of a solution.

12. The method as claimed in claim 1, wherein the stabilized composition is a lyophilizate.

13. The method as claimed in claim 1, wherein the stabilized composition is impregnated into an absorbent carrier.