Multi-layer reagent test strip

• US 6,555,061 B1
• Filed: 10/05/2000
• Issued: 04/29/2003
• Est. Priority Date: 10/05/2000
• Status: Expired due to Term

• Current Assignee: Cilag Gmbh International (Johnson & Johnson)
• Original Assignee: Lifescan Incorporated (Duv Holding Corporation)
• Inventors: Rice, Edward Gray, Leong, Koon-wah, Yu, Yeung Siu
• Primary Examiner(s): ALEXANDER, LYLE
• Application Number:
  US09/684,716
• Time in Patent Office: 936 Days
• Field of Search: 436/169-170, 436/177-178, 436/95, 422/58, 422/61
• US Class Current: 422/412
• CPC Class Codes: G01N 33/526 the element being adapted for a specific analyte
• CPC Class Codes: G01N 33/66 involving blood sugars, e.g. galactose
• CPC Class Codes: Y10T 436/25375 Liberation or purification of sample or separation of material from a sample [e.g., filtering, centrifuging, etc.]
• CPC Class Codes: Y10T 436/255 including use of a solid sorbent, semipermeable membrane, or liquid extraction

Abstract

A reagent test strip for measuring an analyte concentration in a biological fluid has a spreading mesh sandwiched between a support and a reagent matrix. The support has a through hole that is covered by the mesh. In use, a sample of the fluid is applied through the hole in the support to the spreading mesh. The sample then passes through the mesh to the matrix, which contains a reagent that indicates the analyte concentration by causing a corresponding change in reflectance at its free surface. Optionally, an adhesive layer attaches the mesh, and optionally the matrix as well, to the support.

Claims

1. A reagent test strip for use in an apparatus for measuring an analyte concentration in a biological fluid, comprising

(a) a support having a top surface, a bottom surface opposite, and a through hole for passing a sample of the biological fluid,

(b) a mesh, having a first surface adjoining the bottom surface of and covering the hole in, the support, and

(c) a reagent matrix attached to a second surface of the mesh, opposite the first surface, the matrix comprising

(i) a sample receiving surface for receiving the sample from the mesh and passing at least a portion of the sample toward a testing surface opposite to the receiving surface and

(ii) a reagent for indicating the analyte concentration, by creating at the testing surface a change in reflectance that can be related to the analyte concentration;

and

(d) an adhesive layer; and

wherein the reagent matrix is attached to, and separated from, the second surface of the mesh by the adhesive layer such that a capillary gap is present between the mesh and the reagent matrix.

2. The test strip of claim 1 wherein the reagent is adapted for indicating a glucose concentration in the sample.

3. The test strip of claim 1, in which the support comprises a thermoplastic sheet.

4. The test strip of claim 1, in which the top surface of the support and the mesh provide high visual contrast.

5. The test strip of claim 1, in which the mesh is at least one of brightly colored and fluorescent.

6. The test strip of claim 1, in which the mesh is hydrophilic.

7. The test strip of claim 1, in which the mesh is substantially non-absorbing of the biological fluid.

8. The test strip of claim 1, in which the mesh comprises at least one of polyester filament and polyamide filament.

9. The test strip of claim 1, in which the mesh has an open area that exceeds 50% of the total area of the mesh.

10. The test strip of claim 1, in which the mesh is attached to the support with a pressure-sensitive adhesive.

11. The test strip of claim 10, in which the adhesive is not present where the mesh covers the hole.

12. The test strip of claim 10, in which at least a part of the adhesive extends through the mesh and attaches the reagent matrix to the support.

13. The test strip of claim 10, in which the adhesive is hydrophobic.

14. The test strip of claim 1, in which the reagent matrix comprises a polyamide membrane.

15. The test strip of claim 1, in which the reagent matrix is an anisotropic membrane with larger pores near the sample receiving surface and smaller pores near the testing surface.

16. The test strip of claim 2, in which the reagent comprises a dye precursor that forms a chromophore indicative of the glucose concentration.

17. The test strip of claim 16, in which the dye precursor comprises 3-methyl-2-benzothiazolinone hydrazone hydrochloride and dimethylaminobenzoic acid.

18. The test strip of claim 16, in which the dye precursor comprises meta [3-methyl 2-benzothiazolinone hydrazone] N-sulfonyl benzenesulfonate monosodium and 8-anilino-1-naphthalene sulfonic acid.

19. The test strip of claim 17, in which the reagent matrix comprises a polyamide membrane.

20. The test strip of claim 18, in which he reagent matrix comprises an anisotropic membrane with larger pores near the receiving surface and smaller pores near the testing surface.