Catalase (EC 1.11.1.6), is a ubiquitous antioxidant, heme-containing peroxisomal homo-tetrameric enzyme that has a detoxification role by catalyzing the decomposition of the toxic cellular by-product hydrogen peroxide (H2O2) to water and oxygen. Hydrogen peroxide is formed in eukaryotic cells as a by-product of various oxidase and superoxide dismutase reactions. Hydrogen peroxide is metabolized by Catalase and also Glutathione peroxidase. Hydrogen peroxide is highly deleterious to cells, and its accumulation causes oxidation of cellular components such as DNA, proteins, and lipids leading to mutagenesis and cell death. Therefore removal of the hydrogen peroxide from cells by Catalase provides protection against oxidative damage. The highest levels of Catalase in humans are found in the liver, kidney and erythrocytes. Defects in the Catalase gene are the cause of acatalasia (ACATLAS); also known as an atalasemia. This disease is characterized by the absence of Catalase activity in red blood cells and is often associated with ulcerating oral lesions. To measure catalase activity based on fluorometric method use our Catalase (CAT) Activity Assay (Fluorometric) (Cat. No. ZX-33102-96)