Glucose-6-phosphate dehydrogenase (G6PDH) is a cytosolic enzyme that catalyzes the first step in the pentose phosphate pathway. This pathway includes converting glucose to ribose-5-phosphate, a precursor to RNA, DNA, ATP, CoA, NAD, and FAD. The pathway also generates NADPH. G6PDH deficiency, the most common enzyme deficiency worldwide, causes a spectrum of diseases including neonatal hyperbilirubinemia, acute hemolysis, and chronic hemolysis. G6PDH activity has been shown to be upregulated in rat and mouse models of obesity, hyperglycemia, and hyperinsulinemia. Cayman’s Glucose-6-Phosphate Dehydrogenase Assay provides a fluorescence-based method for detecting G6PDH activity in a variety of samples including erythrocyte lysates, tissue homogenates, and cell culture samples.