Direct Automated Determination of Glucose by a Glucose Oxidase-peroxidase System.

THE DETERMINATION of glucose by the glucose oxidase-peroxidase system has been simplified by Hill and Kessler (2) with the use of an automated system first described by Skeggs (1). Wincy and Marks (3) have also developed a method using o-tolidine in the automated system. These procedures require a large quantity of sample and use of a dialyzer to separate the protein before color development. The direct micro glucose oxidase manual method developed by Kingsley and Getchell (4) for the determination of glucose in plasma without protein removal or dialysis has been adapted for use with the present AutoAnalyzer equipment.* In all of the methods abo e, glucose oxidase promotes the oxidation of glucose by molecular ox gen to gluconic acid and hydrogen peroxide. The hydrogen peroxide formed is used to oxidize o-dianisidine to an amber color in the presence of peroxidase (Fig. 1). The o-dianisidine dye has been combined with the enzyme mixture to give only one reagent to mix with the plasma as it passes through the automated system. Several drops of Tween 20 are added to the reaction mixture