DETERMINATION OF SUPEROXIDE DISMUTASE ACTIVITY AND ACTIVE OXYGEN

PROBLEM TO BE SOLVED: To measure the subject activity by adding a specific tetrazolium compound and a superoxide dismutase to a superoxide anion generating system, making both reactants to compete with each other and measuring absorbance of the produced formazan. SOLUTION: A tetrazolium compound represented by the formula (R to R are each H, nitro, an alkoxyl or a halogen; M is an alkali metal or ammonium) and a superoxide dismutase enzyme are added to a superoxide anion- generating system. Thereby, reactions of the tetrazolium compound and the enzyme with the superoxide anion are made to compete with each other and the tetrazolium compound is reduced by the superoxide anion and absorbance of the produced formazan is measured to determine the objective superoxide dismutas(SOD) enzyme activity. Furthermore, SOD activity determination is useful for development of research field for exploring relationship between SOD or active oxygen and health in medical care, clinical examination, development or the like, of functional foods.