US4994238A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Constant volume chemical analysis test device
Assignee: Roche Diagnostics Corp
•
Filing: 1988-06-09
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Granted: 1991-02-19
•
Expires: 2008-06-09
Abstract
Abstract The multilayer test devices of this invention comprise, in order, (a) an absorbent layer; (b) a waterproof barrier layer; and (c) a quickly absorbent reagent layer having a determinate volume. The absorbent and barrier layers each include an aperture functionally aligned for application of a test sample through the absorbent and barrier layers and onto the surface of the reagent layer. The reagent layer contains one or more reagents which produce a detectable species in the presence of an analyte. The reagent layer preferably comprises an asymmetrical filter, which localizes cellular components of the test sample at or near the surface of the filter, while facilitating saturation of the filter by non-cellular sample components. Preferred embodiments of the test devices include devices for testing glucose, alcohol, cholesterol, or other analytes in whole blood.
Inventors
- 👤 George M. Daffern
- 👤 Tracy N. Thompson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:53
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/52; G01N33/525; C; C12; C12Q; C12Q1/00; C12Q1/54
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
99 words
A multilayer testing device comprising, in sequential contact, (a) an absorbent layer; (b) a waterproof barrier layer; and (c) a quickly absorbent reagent matrix layer having a determinate volume, and containing therein at least one reagent which produces a detectable species in the presence of an analyte; wherein the absorbent and barrier layers each include an aperture functionally aligned for application of a test sample through the absorbent and barrier layers and onto a surface of the reagent layer and the reagent layer comprises an asymmetrically porous membrane having progressively finer filtration with increased distance from the barrier layer.
Claim 2
Dependent Claim
99 words
A multilayer testing device comprising, in sequential contact, (a) an absorbent layer; (b) a waterproof barrier layer; and (c) a quickly absorbent reagent matrix layer having a determinate volume, and containing therein at least one reagent which produces a detectable species in the presence of an analyte; wherein the absorbent and barrier layers each include an aperture functionally aligned for application of a test sample through the absorbent and barrier layers and onto a surface of the reagent layer and the reagent layer comprises an asymmetrically porous membrane having progressively finer filtration with increased distance from the barrier layer.
Claim 3
Dependent Claim
120 words
A multilayer assay device for determining glucose in a whole blood sample, comprising, in sequential contact, (a) an absorbent layer; (b) a waterproof barrier layer; (c) a reagent matrix layer comprising an asymmetrically porous membrane which provides progressively finer filtration with increased distance from the barrier layer, and which contains at least one reagent which reacts with glucose in a liquid sample to produce a detectable species; and (d) a support layer including an aperture which allows the reagent matrix layer contact to the atmosphere; wherein the barrier layer and absorbent layer each contain an aperture which is functionally aligned to facilitate the deposition of a liquid test sample through the apertures and onto the surface of the reagent layer.
Claim 4
Dependent Claim
120 words
A multilayer assay device for determining glucose in a whole blood sample, comprising, in sequential contact, (a) an absorbent layer; (b) a waterproof barrier layer; (c) a reagent matrix layer comprising an asymmetrically porous membrane which provides progressively finer filtration with increased distance from the barrier layer, and which contains at least one reagent which reacts with glucose in a liquid sample to produce a detectable species; and (d) a support layer including an aperture which allows the reagent matrix layer contact to the atmosphere; wherein the barrier layer and absorbent layer each contain an aperture which is functionally aligned to facilitate the deposition of a liquid test sample through the apertures and onto the surface of the reagent layer.
Claim 5
Dependent Claim
22 words
An assay device according to claim 2 wherein the reagent comprises 3,5-Dimethylaminobenzoic acid (DMAB), 3-Methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH), glucose oxidase, and peroxidase.
Claim 6
Dependent Claim
49 words
An element in a multilayer test device comprising an absorbent, asymmetrically porous membrane providing progressively finer filtration with distance from a sample receiving surface, which membrane has a determinate saturation volume, and which acts to filter cellular components of a test sample at or near the sample receiving surface.
Claim 7
Dependent Claim
49 words
An element in a multilayer test device comprising an absorbent, asymmetrically porous membrane providing progressively finer filtration with distance from a sample receiving surface, which membrane has a determinate saturation volume, and which acts to filter cellular components of a test sample at or near the sample receiving surface.
Claim 8
Dependent Claim
23 words
An element according to claim 4 further including one or more reagents which produce a detectable species in the presence of an analyte.
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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) | 1994-02-18 | 1994-08-20 | 1995-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-18 | 1998-08-20 | 1999-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-18 | 2002-08-20 | 2003-02-19 | $7700.00 | Window Closed / Lapsed |