Biological analyzer and method

• US 3,919,051 A
• Filed: 07/11/1974
• Issued: 11/11/1975
• Est. Priority Date: 07/11/1974
• Status: Expired due to Term

• Current Assignee: Gerald D. Rork, Leroy D. Nelson, Robert B. Koch
• Original Assignee: Gerald D. Rork, Leroy D. Nelson, Robert B. Koch
• Inventors: Rork, Gerald D., Koch, Robert B., Nelson, Leroy D.
• Primary Examiner(s): Monacell, A. Louis
• Assistant Examiner(s): Fan, C. A.
• Application Number:
  US05/487,709
• Time in Patent Office: 488 Days
• Field of Search: 195/13.5R,127,136,139
• US Class Current: 435/14
• CPC Class Codes: G01N 33/4915 using flow cells flow cytometry G01N15/14

Abstract

A continuous flow method and apparatus for the determination of glucose in a biological fluid by the oxygen depletion method is provided. The biological fluid sample, along with a carrier solution, are combined and introduced into a chamber containing gel-immobilized glucose oxidase. The mixture is caused to flow sequentially through the immobilized glucose oxidase and a connecting passage the outlet of which is disposed such that the fluid impinges on an oxygen-permeable membrane where the oxygen diffusing therethrough drains sensed electrochemically. The effluent solution drians and the system is regenerated by flushing with a quantity of the reagent solution. The glucose oxidase is immobilized in a manner which allows many tests to be run without any significant loss of enzyme thereby accomplishing a considerable cost reduction in the tests.

Claims

1. A FLOW THROUGH METHOD FOR DETERMINING THE CONCENTRATION OF A COMPONENT OF INTEREST IN A SAMPLE WHEREIN THE DETECTION OF THE CONCENTRATION OR CHANGE THEREIN OF A GASEOUS INDICATING SPECIES FOLLOWING AN ENZYME-CATALYZED REACTION IS INDICATIVE OF THE CONCENTRATION OF THE COMPONENT OF INTEREST, SAID METHOD COMPRISING THE STEPS OF:

COMBINING SAID SAMPLE WITH A CARRIER SOLUTION, CAUSING THE COMBINED SOLUTION TO FLOW PAST A QUANTITY OF AN ENZYME SELECTED TO CATALYZETHE DESIRED REACTION, WHEREIN SAID ENZYME IS IMMOBILIZED IN A MANNER WHICH ALLOWS FREE CONTACT BETWEEN THE COMPONENTS IN SAID COMBINED SOLUTION AND THE ENZYME MOLECULES OCCASIONING LITTLE OR NO LOSS OF ENZYME THEREBY, AFTER SAID REACTION IS SUBSTANTIALLY COMPLETE, CAUSING THE REACTED SOLUTION TO IMPINGE UPON A MEMBRANE SELECTIVELY PERMEABLE TO SAID GASEOUS INDICATING SPECIES AT AN ANGLE WITH SAID MEMBRANE, MONITORING THE CONCENTRATION OF SAID INDICATING SPECIES DIFFUSING THROUGH SAID MEMBRANE, GENERATING AN OUTPUT INDICATIVE OF THE CONCENTRATION SAID INDICATING SPECIES,

2. The method of claim 1, including the step of:

flushing the entire system with an additional amount of said carrier solution thereby regenerating the original conditions prior to the introduction of a subsequent sample.

3. The method of claim 1, including the step of:

controlling the velocity in contacting said immobilized enzyme and said diffusion membrane so that the time interval between the start of the reaction and the measurement of the concentration of the indicating species is fixed.

4. The method of claim 1 wherein said reacted solution is caused to impinge on said membrane such that said membrane is continually cleansed by said reacted solution.

5. A flow-through chemical analysis apparatus for determining the concentration of a component of interest in a sample wherein the detection of the concentration of an indicating species following an enzyme-catalyzed reaction is indicative of the concentration of the component of interest in the sample, said apparatus comprising:

a first chamber for containing an amount of an immobilized enzyme disposed therein in a manner which allows free contact between said enzyme and a solution flowing therethrough to thereby catalyze said enzyme-catalyzed reaction;

means for introducing a carrier solution into said first chamber;

means for introducing a sample into said solution;

a second chamber for receiving said solution from said first chamber;

sensor means for detecting said indicating species in said solution, said sensor means being separated from the said second chamber by a membrane permeable to said indicating species;

flow means connecting the outlet of said first chamber with said second chamber, in a manner which causes said solution to impinge on said membrane at an angle with said membrane;

means for generating an output from said sensor related to the concentration of said indicating species;

drain means for removing said solution after contacting said membrane; and

transducing means for transducing said output into one indicative of the concentration of the component in the sample sought to be determined.

6. THE APPARATUS OF CLAIM 5 WHEREIN SAID FIRST CHAMBER IS IN THE FORM OF AN ENCLOSED PACKED COLUMN.

7. The apparatus as claimed in claim 5 wherein said system is a gravity flow-through system, wherein said reagent-containing solution is fed to the top of said column at an adjustable rate and wherein said second chamber is disposed in a manner which allows it to drain also by gravity.

8. The apparatus as claimed in claim 5 further comprising:

means to control the rate of flow of said solution through said first and said second chambers.

9. The apparatus as claimed in claim 5 wherein said means for supplying said sample is an injection port wherein an accurately determined amount of such sample may be injected into said solution.

10. The apparatus of claim 5 wherein said sensor is an electrochemical detector and said indicating species to be detected is a dissolved gas, said detector having a sensoring electrode disposed opposite and in close proximity to said membrane.

11. The apparatus as claimed in claim 5 Wherein the outlet of flow means is disposed in a manner which causes said solution to impinge on said membrane at right angles to said membrane opposite the location of said sensor.