DETERMINATION OF GLYCOPROTEIN AND GLYCOSYLATED HEMOGLOBIN IN BLOOD
 Inventor: Paul Shieh, 43513 Greenhills Way, Fremont, Calif. 94539
 Appl. No.: 08/914,283  Filed: Aug. 18, 1997
 Int. CI. COIN 27/26
 U.S. CI 205/792; 205/778; 204/403
 Field of Search 204/403; 205/792,
205/777.5, 778; 435/817
 References Cited
U.S. PATENT DOCUMENTS
5,366,868 11/1994 Sakamoto 435/10
5,437,999 8/1995 Diebold et al 435/287.9
5,470,752 11/1995 Burd et al 436/87
5,639,672 6/1997 Burd et al 436/525
5,695,949 12/1997 Galen et al 435/14
McFarland, et al, "Nonenzymatic Glucosylation of Serum Proteins in Diabetes Mellitus" Diabetes, vol. 28, Nov. 1979, 1011-1013.
Kennedy, et al, "Non-Enzymatically Glycosylated Serum Protein in Diabetes Mellitus: An Index of Short-Term Glycaemia" Diabetologia (1981) 21: 94-98.
Johnson, et al, "Fructosamine: a new approach to the estimation of serum glycosylprotein. An index of diabetic control" Clinica Chimica Acta, 127 (1982) 87-95 month unknown.
Primary Examiner—T. Tung
Assistant Examiner—Alex Noguerda
Attorney, Agent, or Firm—Marvin S. Aronoff
A method of determining the concentration of glycoproteins and glycosylated hemoglobin in whole blood and whole blood components by means of an amperometric biosensor and an amperometric biosensor for this determination are provided. In one embodiment, whole blood is introduced into a version of an amperometric sensor having a component that removes erythrocytes. Redox mediators are used to obtain a current flow based on the oxidation of fructosamine derivatives that can be correlated with the concentration of glycosylated proteins in the fraction of the blood from which erythrocytes have been excluded. To obtain the concentration of glycosylated hemoglobin, whole blood is introduced into a version of the sensor which includes a component that produces lysis of the erythrocytes yielding a current flow proportional to the total quality of glycosylated proteins including glycosylated hemoglobin. The glycosyltaed hemoglobin concentration is obtained by subtracting the glycoprotein concentration in the absence of erythrocytes from the glycoprotein concentration of the lysed whole blood. The sensor generally comprises a sensing electrode having a first redox mediator dispersed in an electrically conductive medium such as an electrically conductive graphite formulation; a reference electrode such as a standard silver-silver chloride electrode; a reagent strip containing a pH buffer and a second redox mediator system in a gel medium; and a whole blood treatment component consisting of either a membrane or other means to filter erythrocytes from whole blood or a means to lyse erythrocytes. In a preferred form, that has high sensitivity, the sensing electrode and the reference electrode may be formed as coatings on separate non-conductive strips such as polyester film with these strips arranged so that they form "the bread" of a sandwich in which the electrode coatings are face-to-face and the reagent strip and the filtration or lysing component form the "filling" of the sandwich. The filtration or cell lysing component covers an opening in the reference electrode through which samples are introduced, and is superimposed on the reagent strip.
28 Claims, 3 Drawing Sheets