US4223089A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and diagnostic device for the determination of ammonia and of substrates which react with the formation of ammonia
Assignee: Roche Diagnostics GmbH
•
Filing: 1979-04-30
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Granted: 1980-09-16
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Expires: 1999-04-30
Abstract
Abstract Diagnostic device for the determination of ammonia having a handle, an ammonia indicator layer thereon and an alkaline buffer-containing reaction layer positioned above the indicator layer a distance of 10 to 200 microns by a spacer member. The reaction layer is readily separated from the indicator layer to reveal the latter at the end of the ammonia test.
Inventors
- 👤 Anselm Rothe
- 👤 Adolf K. Selle
- 👤 Hans-Rudolf Lange
- 👤 Walter Rittersdorf
- 👤 Wolfgang Werner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:24
CPC Classifications
C; C07; C07D; C07D213/00; C07D213/02; C07D213/04; C07D213/06; C07D213/16; C07D213/20; C07D213/24; C07D213/26; C07D215/00; C07D215/02; C07D215/04; C07D215/10; C07D217/00; C07D217/02; C07D217/10; C12; C12Q; C12Q1/00; C12Q1/34; C12Q1/58; G; G01; G01N; G01N31/00; G01N31/22; Y; Y10; Y10S; Y10S435/00; Y10S435/805; Y10T; Y10T436/00; Y10T436/17; Y10T436/171538; Y10T436/173845; Y10T436/175383
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
66 words
Diagnostic device for the determination of ammonia and of substrates reacting with the formation of ammonia, comprising handle means, and indicator layer for gaseous ammonia on said handle means, an alkaline buffercontainer reaction layer, said reaction layer being positioned a distance of 10 to 200μ above the indicator layer by spacer means, said spacer means and the reaction layer being readily separable from the indicator layer.
Claim 2
Dependent Claim
66 words
Diagnostic device for the determination of ammonia and of substrates reacting with the formation of ammonia, comprising handle means, and indicator layer for gaseous ammonia on said handle means, an alkaline buffercontainer reaction layer, said reaction layer being positioned a distance of 10 to 200μ above the indicator layer by spacer means, said spacer means and the reaction layer being readily separable from the indicator layer.
Claim 3
Dependent Claim
40 words
Device of claim 1 wherein the spacer means is a woven or knitted mesh or a perforated film with a thickness of 10 to 200μ and a free open surface area of at least 25% of the total surface area.
Claim 4
Dependent Claim
14 words
Device of claim 1 wherein the handle means is made of a synthetic resin.
Claim 5
Dependent Claim
14 words
Device of claim 1 wherein the reaction layer contains a wetting agent and/or stabilizer.
Claim 6
Dependent Claim
19 words
Device of claim 1 wherein the reaction layer is secured to the handle by a hydrophilic, fluid-permeable covering layer.
Claim 7
Dependent Claim
14 words
Device of claim 5 wherein said covering layer is a woven or knitted fabric.
Claim 8
Dependent Claim
18 words
Device of claim 1, wherein the reaction layer contains additional reagents reacting with the substrate to form ammonia.
Claim 9
Dependent Claim
10 words
Device of claim 7 wherein the reaction layer contains urease.
Claim 10
Dependent Claim
11 words
Device of claim 7 wherein the reaction layer contains creatinine deiminase.
Claim 11
Dependent Claim
75 words
Process for detecting ammonia and of substrates reacting with the formation of ammonia in aqueous solution which comprises impregnating the reaction layer of a device according to claim 1 with a drop ammonia or of a substrate reacting with the formation of ammonia thereby causing ammonia to be liberated and act on the indicator layer, stripping off the reaction layer and the spacer means and determining the coloration of the indicator layer visually or photometrically.
Claim 12
Dependent Claim
19 words
Process of claim 10 wherein the reaction layer contains urease which is impregnated with a drop of urea-containing solution.
Claim 13
Dependent Claim
20 words
Process of claim 10 wherein the reaction layer contains creatinine deiminase which is impregnated with a drop of creatinine-containing solution.
Claim 14
Dependent Claim
13 words
Process of claim 10 wherein the reaction layer is covered during the reaction.
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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) | 1983-09-16 | 1984-03-17 | 1984-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-16 | 1988-03-17 | 1988-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-16 | 1992-03-17 | 1992-09-16 | $7700.00 | Window Closed / Lapsed |