An enzymatic method for glucose determination in body fluids.

ENZYMATIC REACTIONS, BECAUSE of their great specificity, are among the most valuable analytic tools at the disposal of the chemist. The method for glucose here described represents an adaptation of such biologic reagents and is a distinct departure from sugar methods now in common use. It is based upon a unique principle communicated to us by Keston (1) prior to publication (2). Traditional methods for glucose depend upon its reducing reactions and are generally based upon the classic work of Benedict (3), Folin and Wu (4), and Hagedorn and Jensen (5). The conspicuous success of these procedures and their resistance to fundamental revision indicates that they will not soon be replaced. This fact does not, however, minimize our constant need for new alternative procedures that possess special advantages of their own. The enzymatic method is based upon beta glucose oxidase or “notatin,” discovered in 1928 by Muller (6) in the molds Aspergillus niger and Penicihium glaucum. He showed that this ferment promoted the oxidation of glucose by molecular oxygen to gluconic acid. Later Franke and Lorenz (7) demonstrated that hydrogen peroxide is produced simultaneously in this reaction. The hydrogen peroxide formed in this way is readily detected with an oxygen acceptor like orthotolidine in the presence of peroxidase, an enzyme easily prepared from horseradish root (8). The great specificity of notatin for glucose confers a special advantage upon the enzymatic procedure not possessed by some reduction methods that may respond to some extent to nonglucose reducing substances present in variable amount in