10-Acetyl-3,7-dihydroxyphenoxazine (N-Acetyl-3,7-dihydroxyphenoxazine), which has been marketed under the name Amplex? Red, is regarded as the best fluorogenic substrate for peroxidase because it is highly specific and stable. The substrate itself is nearly colorless and nonfluorescent until it is oxidized by H2O2 in the presence of horseradish peroxidase (HRP) to become the highly red fluorescent resorufin. High purity resorufin (10062) is also available from Biotium to be used as a standard.
λEx/λEm (pH 9)= 571/585 nm (end product)
ε= 54,000 (end product)
White to off-white solid soluble in DMSO or DMF
Store desiccated at 20°C and protect from light
Amplex Red is a registered trademark of Molecular Probes.