Method and device for determining the concentration of a substance in a fluid

• US 3,936,357 A
• Filed: 08/16/1974
• Issued: 02/03/1976
• Est. Priority Date: 08/16/1974
• Status: Expired due to Term

• Current Assignee: Polaroid Corporation (PLR IP Holdings LLC)
• Original Assignee: Polaroid Corporation (PLR IP Holdings LLC)
• Inventors: Wright, Richard F., Milligan, Terry W.
• Primary Examiner(s): Monacell, A. Louis
• Assistant Examiner(s): Massung, Esther L.
• Application Number:
  US05/498,059
• Time in Patent Office: 536 Days
• Field of Search: 195/103.5, 195/103.5 R, 195/103.5 C, 23/253 TP
• US Class Current: 435/287.8
• CPC Class Codes: C12Q 1/32 involving dehydrogenase
• CPC Class Codes: C12Q 1/48 involving transferase
• CPC Class Codes: C12Q 1/58 involving urea or urease

Abstract

A diagnostic test device comprising an absorbent medium adapted to receive and retain a measured amount of fluid containing the substance to be tested and reagents adapted to contact said fluid to provide a visual determination of the presence and/or concentration of the substance, wherein the absorbent medium comprises a substantially non-swellable material of substantially uniform and constant porosity and thickness.

Claims

1. A device for determining concentration of a substance in a fluid which comprises fluid absorbing means carrying a substantially non-swellable, absorbent material of constant porosity and thickness;

a first and second sheet which are carrying a predetermined amount of reagents adapted to react with said substance to provide a visual indication of the concentration of said substance;

at least one of said first and second sheets is transparent;

said fluid absorbing means intermediate and pivotally secured at each end to said first and second sheets adapted to be moved to a first superposed position where said reagents and said substance coact;

said fluid absorbing means and said first and second sheets adapted to be moved to a second superposed position to contact means for generating the visual indication of the concentration of said substance.

2. The device of claim 1 wherein said reagents comprise enzymes, coenzymes and said means for generating the visual indication of the concentration of said substance comprise colorimetric indicators.

3. The device of claim 1 wherein said absorbent fluid means comprises a microporous filter.

4. The device of claim 1 wherein said fluid comprises blood.

5. The device of claim 4 wherein said reactants comprise hexokinase, glucose-6-phosphate dehydrogenase, nicotinamide adenine dinucleotide phosphate and adenosine triphosphate.

6. The device of claim 2 wherein said colorimetric indicator is incorporated in a precipitation chromatographic sheet.

7. The device of claim 1 wherein one of said transparent sheets includes a scale indicating concentration standards for said substance.

8. The device of claim 1 which includes means for removing undesirable components from said fluid prior to contacting said reagents with said fluid.