Patent US4994238A successfully refreshed from Google Patents.
US4994238A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Constant volume chemical analysis test device
Assignee: Roche Diagnostics Corp
•
Filing: 1988-06-09
•
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 16:47
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.
References Cited (Backward Citations)
US2981606A
Cited
US2912309A
Cited
US3061523A
Cited
US3092465A
Cited
US3158532A
Cited
US3290228A
Cited
US3298789A
Cited
US3476515A
Cited
USRE29725E
Cited
US3558435A
Cited
US3630957A
Cited
US3552928A
Cited
US3847553A
Cited
US3672845A
Cited
US3993451A
Cited
US3783105A
Cited
US3723064A
Cited
US3914174A
Cited
US3992158A
Cited
US3975162A
Cited
US3964870A
Cited
US3917453A
Cited
US3980437A
Cited
USRE30267E
Cited
US4066403A
Cited
US4042335A
Cited
US4144306A
Cited
US4219334A
Cited
US4098574A
Cited
US4166093A
Cited
US4178153A
Cited
US4160008A
Cited
US4176008A
Cited
US4631174A
Cited
US4438067A
Cited
US4256693A
Cited
US4260392A
Cited
US4298688A
Cited
US4281062A
Cited
US4255384A
Cited
US4250257A
Cited
US4211845A
Cited
US4231754A
Cited
US4292272A
Cited
US4387990A
Cited
US4477575A
Cited
US4477575B1
Cited
US4318985A
Cited
US4594224A
Cited
US4391906A
Cited
US4391905A
Cited
US4478942A
Cited
US4427632A
Cited
US4587099A
Cited
US4452887A
Cited
US4390343A
Cited
US4363874A
Cited
US4361648A
Cited
US4540670A
Cited
US4476222A
Cited
US4478944A
Cited
US4604264A
Cited
EP0123443A2
Cited
US4543338A
Cited
US4637978A
Cited
US4594327A
Cited
US4668472A
Cited
US4824639A
Cited
US4532107A
Cited
US4632901A
Cited
US4621049A
Cited
US4786596A
Cited
US4678757A
Cited
US4647430A
Cited
US4780280A
Cited
US4738823A
Cited
EP0256806A2
Cited
US4774192A
Cited
US4814142A
Cited
US4818677A
Cited
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 |