US4812399A
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Analytical element and method for the determination of creatinine or creatine
Assignee: Clinical Diagnostic Systems Inc
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Filing: 1986-04-21
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Granted: 1989-03-14
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Expires: 2006-04-21
Abstract
Abstract An analytical element can be used for the determination of either creatinine or creatine or both. The element contains creatinine amidohydrolase, creatine amidinohydrolase and sarcosine oxidase, and a leuco dye which is capable of providing a detectable dye in the presence of hydrogen peroxide and a peroxidative substance. The creatine amidinohydrolase is present in a manner such that it is substantially inert to the leuco dye. The creatinine amidohydrolase is present in a rate limiting amount. By measuring the amount of dye formation at particular times during the assay, either or both of the analytes can be determined with the same element.
Inventors
- 👤 John C. Mauck
- 👤 Linda A. Mauck
- 👤 Gary E. Norton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 02:16
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/34; G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/70; Y; Y10; Y10S; Y10S435/00; Y10S435/81
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
89 words
An analytical element for the determination of either creatinine or creatine comprising an absorbent carrier material containing creatinine amidohydrolase, creatine amidinohydrolase, sarcosine oxidase and a leuco dye which is capable of providing a detectable dye in the presence of hydrogen peroxide and a peroxidative substance, either or both of said creatine amidinohydrolase and leuco dye being present in encapsulated form or, both being physically isolated from each other until an assay for creatinine or creatine is carried out, and said creatinine amidohydrolase being present in a rate limiting amount.
Claim 2
Dependent Claim
89 words
An analytical element for the determination of either creatinine or creatine comprising an absorbent carrier material containing creatinine amidohydrolase, creatine amidinohydrolase, sarcosine oxidase and a leuco dye which is capable of providing a detectable dye in the presence of hydrogen peroxide and a peroxidative substance, either or both of said creatine amidinohydrolase and leuco dye being present in encapsulated form or, both being physically isolated from each other until an assay for creatinine or creatine is carried out, and said creatinine amidohydrolase being present in a rate limiting amount.
Claim 3
Dependent Claim
21 words
The element of claim 1 wherein said creatine amidinohydrolase and leuco dye are physically located in separate zones of said element.
Claim 4
Dependent Claim
24 words
The element of claim 1 wherein said creatine amidinohydrolase and creatinine amidohydrolase are present in an activity coverage ratio of at least about 50:1.
Claim 5
Dependent Claim
14 words
The element of claim 1 wherein said leuco dye is a triarylimidazole leuco dye.
Claim 6
Dependent Claim
10 words
The element of claim 1 further comprising a peroxidative substance.
Claim 7
Dependent Claim
71 words
A multilayer analytical element for the determination of either creatinine or creatine comprising a support having thereon, in order, a first reagent layer containing sarcosine oxidase, a rate limiting amount of creatinine amidohydrolase, a peroxidative substance and an imidazole leuco dye which is capable of providing a detectable dye in the presence of said peroxidative substance and hydrogen peroxide, a second reagent layer containing creatine amidinohydrolase, and a porous spreading layer.
Claim 8
Dependent Claim
71 words
A multilayer analytical element for the determination of either creatinine or creatine comprising a support having thereon, in order, a first reagent layer containing sarcosine oxidase, a rate limiting amount of creatinine amidohydrolase, a peroxidative substance and an imidazole leuco dye which is capable of providing a detectable dye in the presence of said peroxidative substance and hydrogen peroxide, a second reagent layer containing creatine amidinohydrolase, and a porous spreading layer.
Claim 9
Dependent Claim
21 words
The element of claim 6 wherein the activity coverage ratio of creatine amidinohydrolase and creatinine amidohydrolase is at least about 50:1.
Claim 10
Dependent Claim
14 words
The element of claim 6 wherein said imidazole dye is a triarylimidazole leuco dye.
Claim 11
Dependent Claim
11 words
The element of claim 6 wherein said peroxidative substance is peroxidase.
Claim 12
Independent Claim
135 words
A method for the determination of either creatinine or creatine comprising the steps of: A. in the presence of a peroxidative substance, contacting a sample of a liquid suspected of containing either creatinine or creatine with an analytical element comprising an absorbent carrier material containing creatinine amidohydrolase, creatine amidinohydrolase, sarcosine oxidase and a leuco dye which is capable of providing a detectable dye in the presence of hydrogen peroxide and a peroxidative substance, either or both of said creatine amidinohydrolase and leuco dye being present in encapsulated form or, both being physically isolated from each other until an assay for creatinine or creatine is carried out, and said creatinine amidohydrolase being present in a rate limiting amount, and B. determining the detectable dye formed as a result of the presence of either creatinine or creatine.
Claim 13
Independent Claim
135 words
A method for the determination of either creatinine or creatine comprising the steps of: A. in the presence of a peroxidative substance, contacting a sample of a liquid suspected of containing either creatinine or creatine with an analytical element comprising an absorbent carrier material containing creatinine amidohydrolase, creatine amidinohydrolase, sarcosine oxidase and a leuco dye which is capable of providing a detectable dye in the presence of hydrogen peroxide and a peroxidative substance, either or both of said creatine amidinohydrolase and leuco dye being present in encapsulated form or, both being physically isolated from each other until an assay for creatinine or creatine is carried out, and said creatinine amidohydrolase being present in a rate limiting amount, and B. determining the detectable dye formed as a result of the presence of either creatinine or creatine.
Claim 14
Dependent Claim
35 words
The method of claim 10 for the kinetic determination of creatinine wherein said detectable dye is measured at least twice after substantially all endogenous creatine has been converted to reaction products after said contacting step.
Claim 15
Dependent Claim
27 words
The method of claim 10 for the determination of creatine wherein said detectable dye is measured prior to substantial conversion of endogenous creatinine after said contacting step.
Claim 16
Dependent Claim
13 words
The method of claim 10 wherein said element further comprises said peroxidative substance.
Claim 17
Dependent Claim
21 words
The method of claim 10 wherein said creatine amidinohydrolase and leuco dye are physically located in separate zones of said element.
Claim 18
Dependent Claim
75 words
The method of claim 10 wherein said element is a multilayer analytical element comprising a support having thereon, in order, a first reagent layer containing said sarcosine oxidase, a rate limiting amount of said creatinine amidohydrolase, a peroxidative substance and an imidazole leuco dye which is capable of providing a detectable dye in the presence of said peroxidative substance and hydrogen peroxide, a second reagent layer containing said creatine amidinohydrolase, and a porous spreading layer.
Claim 19
Dependent Claim
24 words
The method of claim 15 wherein the activity coverage ratio of creatine amidinohydrolase and creatinine amidohydrolase in said element is at least about 50:1.
Claim 20
Dependent Claim
15 words
The method of claim 16 wherein the activity coverage ratio is at least about 100:1.
Claim 21
Dependent Claim
14 words
The method of claim 15 wherein said imidazole dye is a triarylimidazole leuco dye.
Claim 22
Dependent Claim
11 words
The method of claim 10 wherein said peroxidative substance is peroxidase.
Claim 23
Dependent Claim
13 words
The method of claim 10 wherein said liquid is human serum or urine.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-03-13 | 1992-09-12 | 1993-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-13 | 1996-09-12 | 1997-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-13 | 2000-09-12 | 2001-03-14 | $7700.00 | Window Closed / Lapsed |