Visual blood glucose test strip

• US 6,162,397 A
• Filed: 08/13/1998
• Issued: 12/19/2000
• Est. Priority Date: 08/13/1998
• Status: Expired due to Term

• Current Assignee: Cilag Gmbh International (Johnson & Johnson)
• Original Assignee: Lifescan Incorporated (Duv Holding Corporation)
• Inventors: Diemmy Dao, Mimi, Jurik, Franklin A., Chang, Carol, Stubbs, Andrea
• Primary Examiner(s): Warden, Jill
• Application Number:
  US09/133,857
• Time in Patent Office: 859 Days
• Field of Search: 422/56, 422/57, 422/58, 436/169, 436/170, 436/95
• US Class Current: 422/423
• CPC Class Codes: G01N 33/523 the element being adapted for a specific analyte
• CPC Class Codes: G01N 33/66 involving blood sugars, e.g. galactose
• CPC Class Codes: Y10T 436/144444 Glucose

Abstract

A visual blood glucose test strip has two membranes that each incorporate a reagent that reacts with glucose in a blood sample applied to the membranes to cause a color change. One of the membranes also includes an inhibitor and a dye. A blood sample applied to the strip causes the two membranes to form two different colors. Comparing the colors to a calibrated color chart permits a user to determine the glucose concentration in the blood sample.

Claims

1. A visual blood glucose test strip, comprising

a) a two-sided spreading layer for accepting a blood sample on a first side and passing the sample to a second side, opposite;

b) an intermediate layer comprising first and second membranes, substantially side-by-side, each having a top major surface adjoining the second side of the spreading layer to receive a part of the blood sample and each containing a reagent that can react with glucose in the sample, as it passes through the membrane, to cause a color change in the reagent, the second membrane further comprising an inhibitor and an inert dye, and

c) a support layer to support the other layers and to permit any color changes in the membranes to be visible through it.

2. The strip of claim 1 in which the spreading layer comprises a hydrophilic polyester woven fabric.

3. The strip of claim 1 in which the spreading layer comprises a sintered polyethylene.

4. The strip of claim 1 in which each of the membranes of the intermediate layer is an asymmetric polysulfone membrane.

5. The strip of claim 1 in which the reagent in each membrane is the same.

6. The strip of claim 5 in which the reagent comprises 3-methyl-2-benzothiazolinone hydrazone hydrochloride combined with 3,3-dimethylaminobenzoic acid (MBTH-DMAB).

7. The strip of claim 5 in which the reagent comprises 3-methyl-2-benzothiazolinone hydrazone hydrochloride combined with 8-anilino-1-naphthalene sulfonic acid ammonium (MBTH-ANS).

8. The strip of claim 5 in which the reagent comprises meta [3-methyl-2-benzothiazolinone hydrazone] N-sulfonyl benzenesulfonate monosodium combined with 8-anilino-1-naphthalene sulfonic acid ammonium (MBTHSB-ANS).

9. The strip of claim 5 in which the reagent further comprises a soluble polymer.

10. The strip of claim 9 in which the soluble polymer is polyvinylpyrrolidone.

11. The strip of claim 1 in which the inhibitor comprises ascorbic acid.

12. The strip of claim 1 in which the dye comprises Auramine O-anhydrous.

13. The strip of claim 1 in which through holes in the support layer permit any color changes in the membrane to be visible through it.

14. The strip of claim 1 further comprising a cover layer over the spreading layer, with a through hole for applying sample to the spreading layer.

15. The strip of claim 1 further comprising an absorbent layer adjoining the spreading layer for absorbing excess sample.