Single Glucose Oxidase—Peroxidase Reagent for Two-Minute Determination of Serum Glucose

The glucose oxidase—peroxidase procedure for determining glucose in serum or plasma has been modified by changing the assay pH to 5.5, altering the ratio of glucose oxidase to peroxidase, and using a soluble chromogen, p-diphenylamine sulfonate, to prepare a single complete reagent that develops stable color within 2 min without deproteinization. Most interferences were inconsequential. Serum that clearly is icteric or hemolytic is Somogyi-precipitated. Recovery was 99% and the CV was 3.3%. Correlation with results obtained by the neocuproine procedure, with use of the SMA 12/60, averaged 12 mg/dl lower values (r2 = 0.98).