Hydrogen Peroxide is a reactive oxygen metabolic byproduct that serves as a key regulator for a number of oxidative stress-related states. Functioning through NF-κB and other factors, hydroperoxide-mediated pathways have been linked to asthma, inflammatory arthritis, atherosclerosis, diabetic vasculopathy, osteoporosis, neuro-degenerative diseases, Down’s syndrome and immune system diseases. BioVision’s Hydrogen Peroxide Assay Kit is a highly sensitive, simple, direct and HTS-ready colorimetric and fluorometric assay for measuring H₂O₂ in biological samples. In the presence of Horse Radish Peroxidase (HRP), the OxiRed Probe reacts with H₂O₂ to produce product with color (λmax = 570 nm) and red-fluorescent (Ex/Em=535/587 nm). The kit can perform 200 reactions by fluorometric method or 100 reactions by colorimetric method. The detection limit can be as low as 2 pmol per assay (or 40 nM concentration) of H₂O₂ in the sensitive fluorometric assay.