Patent EP0509135A1 successfully refreshed from Google Patents.
US5160436A
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Asymmetric sandwich membrane system having reduced ascorbate interference
Assignee: Bayer Corp
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Filing: 1991-04-30
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Granted: 1992-11-03
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Expires: 2011-04-30
Abstract
Abstract Disclosed is a diagnostic test device which comprises a fluid permeable structural support member having on one side thereof a layer of a macroporous membrane comprising polyethyleneimine impregnated with iodate ion and on the other side of the support member having a layer of a microporous membrane having dispersed therein a chromogenic indicator capable of providing a colored response upon being oxidized. The intensity of the colored response is less subject to ascorbate interference due to the activity of the iodate ion.
Inventors
- 👤 Karlheinz Hildenbrand
- 👤 Herbert Hugl
- 👤 Rolf Dhein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:48
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/54; G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/52; G01N33/525
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
71 words
A diagnostic test device for detecting the presence of an analyte in a fluid sample which device comprises a fluid permeable support member having a layer on one side thereof of a macroporous membrane comprising polyethyleneimine having impregnated therein iodate ion and on the other side of the support member having a layer of a microporous membrane having dispersed therein a chromogenic indicator which provides a colored response upon being oxidized.
Claim 2
Dependent Claim
71 words
A diagnostic test device for detecting the presence of an analyte in a fluid sample which device comprises a fluid permeable support member having a layer on one side thereof of a macroporous membrane comprising polyethyleneimine having impregnated therein iodate ion and on the other side of the support member having a layer of a microporous membrane having dispersed therein a chromogenic indicator which provides a colored response upon being oxidized.
Claim 3
Dependent Claim
27 words
The device of claim 1 wherein the macroporous membrane comprises a blend of polyethyleneimine, polyacrylonitrile, polyurethane and polyvinyl acetate and the microporous membrane is comprised of polyacrylonitrile.
Claim 4
Dependent Claim
28 words
The diagnostic device of claim 1 wherein the macroporous membrane contains pores greater than 0.2μ in diameter and the microporous membrane contains pores up to 0.2μ in diameter.
Claim 5
Dependent Claim
16 words
The diagnostic test device of claim 1 wherein iodic acid is the source of iodate ion.
Claim 6
Dependent Claim
34 words
A method for the detection of an analyte in a liquid sample suspected of containing ascorbate ion which comprises applying said liquid sample to the macroporous layer of the test device of claim 1.
Claim 7
Dependent Claim
17 words
The method of claim 5 wherein the analyte is glucose and the chromogenic indicator is 3,3',5,5'tetramethyl benzidine.
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) | 1995-11-03 | 1996-05-04 | 1996-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-03 | 2000-05-04 | 2000-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-11-03 | 2004-05-04 | 2004-11-03 | $7700.00 | Window Closed / Lapsed |