US4188465A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stabilized urease composition
Assignee: Roche Diagnostics GmbH
•
Filing: 1977-03-25
•
Granted: 1980-02-12
•
Expires: 1997-03-25
Abstract
Abstract Stabilized urease compositions are provided comprising urease and, as a stabilizing agent, a mixture of glutathione, ethylenediamine-tetraacetic acid, and citrate, preferably in a weight ratio of 1:0.5-5:0.5-3:0.5-3.
Inventors
- 👤 Walter Schneider
- 👤 Albert Roder
- 👤 Hans Mollering
- 👤 Ingeborg Gutmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:07
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/58; C12N; C12N9/00; C12N9/14; C12N9/78; C12N9/80; C12N9/96
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
36 words
Stabilized urease composition comprising urease of a specific activity of from 25-1500 U/mg and, as a stabilizing agent, a stabilizing mixture of glutathione, ethylenediamine-tetraacetic acid and citrate, wherein said citrate is present in stabilizingly effective amount.
Claim 2
Dependent Claim
36 words
Stabilized urease composition comprising urease of a specific activity of from 25-1500 U/mg and, as a stabilizing agent, a stabilizing mixture of glutathione, ethylenediamine-tetraacetic acid and citrate, wherein said citrate is present in stabilizingly effective amount.
Claim 3
Dependent Claim
23 words
Urease composition a claimed in claim 1, wherein said composition contains urease, glutathione, ethylenediaminetetraacetic acid and citrate in a weight ratio of 1:0.5-5:0.5-3:0.5-3.
Claim 4
Dependent Claim
13 words
Urease composition as claimed in claim wherein said urease is dextran pre-tested urease.
Claim 5
Dependent Claim
14 words
Urease composition as claimed in claim 1 wherein said urease is in lyophilized form.
Claim 6
Dependent Claim
21 words
Urease composition as claimed in claim 1 wherein said urease is in the form of a solution in a glycerol/water mixture.
Claim 7
Dependent Claim
23 words
Reagent for the detection of urea comprising a stabilized urease as claimed in claim 1, and a system for the detection of ammonia.
Claim 8
Dependent Claim
15 words
Reagent as claimed in claim 6 additionally containing a binding agent, carrier and buffer substance.
Claim 9
Dependent Claim
18 words
Reagent as claimed in claim 6 additionally containing a stabilizer for the system for the detection of ammonia.
Claim 10
Dependent Claim
37 words
Reagent as claimed in claim 6 comprising a carrier paper or carrier film impregnated with the stabilized urease and the system for the detection of ammonia or coated on in the form of a binding agent-containing layer.
Claim 11
Dependent Claim
27 words
Reagent as claimed in claim 6 wherein the system for the determination of urea contains at least one pH indicator and optionally a wetting agent and/or buffer.
Claim 12
Dependent Claim
28 words
Reagent as claimed in claim 6 wherein the system for the determination of ammonia comprises glutamic acid dehydrogenase, an alpha-ketoglutarate, reduced nicotinamide-adenine dinucleotide, adenosine diphosphate and a buffer.
Claim 13
Dependent Claim
25 words
Reagent as claimed in claim 6 wherein the system for the determination of ammonia comprises phenol or salicylic acid, sodium nitroferric cyanide and sodium hypochlorite.
Claim 14
Dependent Claim
42 words
Process for preparing a stabilized urease composition which comprises adding to urease of a specific activity of from 25-1500 U/mg, stabilizingly effective amounts of a stabilizing mixture of glutathione, ethylenediamine-tetraacetic acid and citrate, wherein said citrate is present in stabilizingly effective amount.
Claim 15
Dependent Claim
42 words
Process for preparing a stabilized urease composition which comprises adding to urease of a specific activity of from 25-1500 U/mg, stabilizingly effective amounts of a stabilizing mixture of glutathione, ethylenediamine-tetraacetic acid and citrate, wherein said citrate is present in stabilizingly effective amount.
Claim 16
Dependent Claim
20 words
Process as claimed in claim 13 wherein said urease is treated with dextran prior to the addition of said mixture.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-02-11 | 1983-08-13 | 1984-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-11 | 1987-08-13 | 1988-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-11 | 1991-08-13 | 1992-02-12 | $7700.00 | Window Closed / Lapsed |