Dyes and Fluorophores 

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.

• λ_Ex/λ_Em (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
• C₁₄H₁₁CNO₄
• MW: 257.24
• [119171-73-2]

Amplex Red is a registered trademark of Molecular Probes.