Constant volume chemical analysis test device

• US 4,994,238 A
• Filed: 06/09/1988
• Issued: 02/19/1991
• Est. Priority Date: 06/09/1988
• Status: Expired due to Fees

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Boehringer Mannheim Corporation
• Inventors: Daffern, George M., Thompson, Tracy N.
• Primary Examiner(s): WARDEN, JILL ALICE
• Assistant Examiner(s): Johnston, Jill
• Application Number:
  US07/205,230
• Time in Patent Office: 985 Days
• Field of Search: 422/56, 422/57, 422/58, 436/170
• US Class Current: 422/422
• CPC Class Codes: C12Q 1/54 involving glucose or galactose
• CPC Class Codes: G01N 33/525 Multi-layer analytical elements

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.

Claims

1. 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.

2. 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.

3. 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.

4. 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.

5. An element according to claim 4 further including one or more reagents which produce a detectable species in the presence of an analyte.