Erythrocyte glucose-6-phosphate dehydrogenase activity is measured with a centrifugal analyzer by use of a commercial reagent kit and of the reaction glucose-6-phosphate + NADP+ leads to 6-phosphogluconolactone + NADPH. Rate of production of NADPH is measured and related to hemoglobin concentration. Maleimide is added to inhibit further production of NADPH in a secondary reaction by endogenous ...