Bio-selective electrode probes using tissue slices

• US 4,216,065 A
• Filed: 06/18/1979
• Issued: 08/05/1980
• Est. Priority Date: 06/18/1979
• Status: Expired due to Term

• Current Assignee: University of Delaware
• Original Assignee: University of Delaware
• Inventors: Rechnitz, Garry A., Meyerhoff, Mark E., Arnold, Mark A.
• Primary Examiner(s): Prescott, Arthur C.
• Application Number:
  US06/049,092
• Time in Patent Office: 414 Days
• Field of Search: 204/1 T, 204/195 B, 204/195 M, 204/195 P, 204/296, 23/230 B, 424/12, 195/103.5 R, 195/103.5 C, 428/213, 156/230, 210/490, 210/500 M
• US Class Current: 205/778
• CPC Class Codes: C12Q 1/002 Electrode membranes
• CPC Class Codes: C12Q 1/005 involving specific analytes or enzymes including groups of enzymes, e.g. oxydases; C12Q1/004 takes precedence
• CPC Class Codes: G01N 27/304 Gas permeable electrodes
• CPC Class Codes: G01N 33/6812 Assays for specific amino acids

Abstract

A bio-selective potentiometric electrode probe for the determination of amino acid concentrations in aqueous liquids comprising an ammonia gas analytical electrode provided at its tip with a closely adjacent thin layer of a fresh animal tissue containing, as a natural constituent thereof, an enzyme effective to catalyze degradation of the specific amino acid in analysis to either ammonia or to an intermediate compound subject to further degradation to ammonia by an additional enzyme, which ammonia is a function of the amino acid concentration in the liquid.

Claims

1. A bio-selective potentiometric electrode probe equipped with a gas-permeable membrane for the determination of the concentration of a preselected amino acid in an aqueous liquid comprising an ammonia gas analytical electrode provided at its tips with a closely adjacent thin layer of a fresh animal tissue containing, as a natural constituent thereof, a preselected enzyme effective to catalyze degradation of said amino acid in analysis to either ammonia or to an intermediate compound subject to further degradation to ammonia in the presence of an additional preselected enzyme, which ammonia is a function of said preselected amino acid concentration in said aqueous liquid, and a dialytic membrane interposed between said gas-permeable membrane and said animal tissue layer.

2. A bio-selective potentiometric electrode probe for the determination of the concentration of a preselected amino acid in an aqueous liquid according to claim 1 wherein said thin layer of said fresh animal tissue and said additional preselected enzyme are both retained closely adjacent said ammonia gas electrode tip by a second dialysis membrane interfacing with said amino acid-containing aqueous liquid.

3. A bio-slective potentiometric electrode probe for the determination of the concentration of glutamine in an aqueous liquid according to claim 1 wherein said fresh animal tissue is a thin slice of pork kidney excised from the cortex region.

4. A bio-selective potentiometric electrode probe for the determination of the concentration of arginine in an aqueous liquid medium according to claim 2 wherein said fresh animal tissue is a thin slice of beef liver and said additional preselected enzyme is urease.

5. In the potentiometric determination of the concentration of a preselected amino acid in an aqueous liquid utilizing an ammonia gas analytical electrode fitted with a gas-permeable membrane having its tip immersed in said aqueous liquid, the improvement comprising maintaining closely adjacent said electrode tip but separated therefrom and from said gas-permeable membrane by a dialytic membrane, a thin layer of a fresh animal tissue containing, as a natural constituent thereof, a preselected enzyme effective to catalyze degradation of said amino acid in analysis to either ammonia or to an intermediate compound subject to further degradation to ammonia in the presence of an additional preselected enzyme, which ammonia is a function of said preselected amino acid concentration in said aqueous liquid.

6. The method of potentiometric determination of the concentration of a preselected amino acid in an aqueous liquid according to claim 5 wherein said thin layer of said fresh animal tissue and said additional preselected enzyme are both retained adjacent said electrode tip by a second dialysis membrane interfacing with said amino acid-containing aqueous liquid.