Glucose-6-phosphate (G6P) plays a key role in the homeostatic regulation of blood glucose levels by participating in glycolysis, glycogen synthesis, gluconeogenesis, and can be metabolized to NADPH, enabling protection against oxidative damage. Disruption of G6P activity leads to glycogen storage disease type I or von Gierke’s disease, a group of inherited metabolic diseases characterized by severe hypoglycemia, growth retardation, and hepatomegaly, due to accumulation of glycogen and fat in the liver. Cayman’s Glucose-6-Phosphate Fluorometric Assay provides a fluorescence-based method for detecting G6P in tissue homogenates and cell culture samples. In the assay, G6PDH catalyzes the oxidation of G6P to 6-phospho-D-gluconate, along with the concomitant reduction of NADP+ to NADPH. NADPH reacts with the fluorometric detector to yield a highly fluorescent product which can be analyzed with an excitation wavelength of 530-540 nm and an emission wavelength of 585-595 nm.