US3869348A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Determination of amylase
Assignee: Pierce Chemical Co
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Filing: 1973-02-26
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Granted: 1975-03-04
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Expires: 1993-02-26
Abstract
Abstract A method for the determination of amylase activity and a useful highly stable color reagent aqueous solution therefore are disclosed. The solution comprises, as a color reagent, an aromatic nitro containing compound such as 3,5-dinitrosalicyic acid, a color stabilizing chelating compound such as ethylenediaminetetraacetic acid, and a hydroxide base. Eliminating the necessity for centrifuging prior to the determination of amylase activity can be achieved by including potassium hydroxide for at least a part of the base in the solution.
Inventors
- 👤 E Melvin Gindler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:15
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/34; C12Q1/40
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
72 words
AN AQUEOUS SOLUTION USEFUL FOR THE DETECTION OF AMYLASE ACTIVITY COMPRISING AN AROMATIC NITRO CONTAINING COMPOUND REDUCIBLE BY LOWER SUGARS TO GIVE A REDUCED COMPOUND HAVING A DIFFERENT COLOR OR COLOR INTENSITY, A COLOR STABILIZER, SUFFICIENT BASE TO RAISE THE PH ABOVE ABOUT 10, AND AT LEAST ABOUT 0.03 MOLE/100 ML OF A HIGHER ALKALI METAL CATION, SAID COLOR STABILIZER BEING AN IMINODIACETIC ACID CONTAINING CHELATING COMPOUND HAVING SUBSTANTIALLY NO REDUCING PROPERTIES.
Claim 2
Dependent Claim
72 words
AN AQUEOUS SOLUTION USEFUL FOR THE DETECTION OF AMYLASE ACTIVITY COMPRISING AN AROMATIC NITRO CONTAINING COMPOUND REDUCIBLE BY LOWER SUGARS TO GIVE A REDUCED COMPOUND HAVING A DIFFERENT COLOR OR COLOR INTENSITY, A COLOR STABILIZER, SUFFICIENT BASE TO RAISE THE PH ABOVE ABOUT 10, AND AT LEAST ABOUT 0.03 MOLE/100 ML OF A HIGHER ALKALI METAL CATION, SAID COLOR STABILIZER BEING AN IMINODIACETIC ACID CONTAINING CHELATING COMPOUND HAVING SUBSTANTIALLY NO REDUCING PROPERTIES.
Claim 3
Dependent Claim
24 words
The aqueous solution of claim 1 wherein the aromatic nitro containing compound is 1,2-dinitrobenzene; 3,4-dinitrobenzoic acid; 3,6-dinitrophthalic acid; 3,5-dinitrosalicylic acid; 2,4,6-trinitro-phenol; 2,4-dinitrophenol; or 5,7-dinitro-8-hydroxynaphthalene-2-sulfonate.
Claim 4
Dependent Claim
15 words
The aqueous solution of claim 2 wherein the aromatic nitro containing compound is 3,5-dinitrosalicylic acid.
Claim 5
Dependent Claim
24 words
The aqueous solution of claim 1 wherein the color stabilizer is ethylene diaminetetraacetic acid, diethylene triamine pentacetic acid or ethylenebis oxyethylene nitrilo tetraacetic acid.
Claim 6
Dependent Claim
14 words
The aqueous solution of claim 4 wherein the color stabilizer is ethylene diaminetetraacetic acid.
Claim 7
Dependent Claim
16 words
The aqueous solution of claim 1 containing at least about 0.04 mol./100 ml. of potassium ion.
Claim 8
Dependent Claim
14 words
The aqueous solution of claim 3 wherein the color stabilizer is ethylene diaminetetraacetic acid.
Claim 9
Dependent Claim
38 words
The aqueous solution of claim 7 containing potassium ions in a coNcentration of at least 0.04 mol./100 ml. of solution and wherein the molar ratio of potassium ion to any sodium ion present is at least about 1.
Claim 10
Dependent Claim
23 words
The aqueous solution of claim 8 wherein the molar ratio of potassium ion to sodium ion, if present, is at least about 1.2.
Claim 11
Dependent Claim
22 words
The composition of claim 9 containing, in addition to the ingredients included therein, salicylate ions, sulfite ions, carbonate ions and hydroxyl ions.
References Cited (Backward Citations)
US3413198A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-03 | 1978-09-02 | 1979-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-03 | 1982-09-02 | 1983-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-03 | 1986-09-02 | 1987-03-04 | $7700.00 | Window Closed / Lapsed |