The Catalase Activity Assay determines the activity of catalase by measuring its ability to reduce hydrogen peroxide. Catalase is an enzyme that protects cells from oxidative damage by decomposing hydrogen peroxide into water and oxygen. This assay introduces the enzyme sample into a hydrogen peroxide solution and measures how effectively it can remove the hydrogen peroxide from solution. The catalase activity in a sample is quantified by detecting the hydrogen peroxide remaining in solution using a fluorogenic probe that can be measured with a spectrophotometer.