Enzymatic microanalysis of glycogen

A specific and simple enzymatic method for the determination of glycogen in tissue, with a detection limit of about 1 microgram glycogen (6.2 nmol glucosyl residues) is described. Glycogen is converted to 6-phosphogluconate by means of amyloglucosidase, hexokinase, and glucose-6-phosphate dehydrogenase. The increase in NADPH is measured fluorometrically. Muscle tissue (5-20 mg) is hydrolysed in hot KOH (5.4 mol/l), neutralized and analysed. The glycogen-glucosyl content in wet rat diaphragm muscle is about 43 mmol/kg.