Our Amplex UltraRed reagent improves upon the performance of our unique Amplex Red reagent, offering brighter fluorescence and enhanced sensitivity on a per-mole basis in peroxidase or peroxidase-coupled enzyme assays. The Amplex UltraRed reagent is also less sensitive to pH, and exhibits improved stability in the presence of hydrogen peroxide (H_2O2) or thiols such as dithiothreitol (DTT).