The ROS-Glo™ H₂O₂ Assay is a homogeneous, fast and sensitive bioluminescent assay that measures the level of hydrogen peroxide (H₂O₂), a reactive oxygen species (ROS), directly in cell culture or in defined enzyme reactions. A derivatized luciferin substrate is incubated with sample and reacts directly with H₂O₂ to generate a luciferin precursor. Addition of ROS-Glo™ Detection Solution converts the precursor to luciferin and provides Ultra-Glo™ Recombinant Luciferase to produce light signal that is proportional to the level of H₂O₂ present in the sample.