Catalase is a ubiquitous enzyme that destroys hydrogen peroxides formed during oxidative stress. Our OxiSelect Catalase Activity Assay Kit measures catalase activity in less than one hour from a variety of samples including blood, cells and tissues. Each kit provides sufficient reagents to perform up to 500 assays in a 96-well microtiter plate. This includes blanks, catalase standards and unknown samples. The OxiSelect Catalase Activity Assay Kit (Fluorometric) provides a 40-fold increase in sensitivity compared to our colorimetric assay.