Glucose in serum and cerebrospinal fluid by direct application of a glucose oxidase method.

Glucose is measured directly in 0.02 ml. of serum or cerebrospinal fluid by reaction with glucose oxidase. The hydrogen peroxide produced reacts with iodide in the presence of a catalyst to form molecular iodine. The iodine color is proportional to the glucose and is measured photometrically. The reaction is carried out directly on serum following preincubation with molecular iodine and can be completed in 15 mm. The results on normal serum average 8 mg./100 ml. lower than those obtained with the Aut-oAnalyzer reduction method. At a glucose concentration of 150 mg./100 ml., the procedure has a coefficient of variation of 1.4%. Recovery of added glucose averaged 98%. Hemolysis, lipemia, or icterus do not interfere.