10-Acetyl-3,7-dihydroxyphenoxazine (N-Acetyl-3,7-dihydroxyphenoxazine or ADHP), which has been marketed under the name Amplex&reg; 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(reacting in a 1:1 stoichiometry) in the presence of horseradish peroxidase (HRP) to become the highly red fluorescent resorufin. H₂O₂ is produced by many enzymatic reactions, and thereforeADHP can be used to detect the activity of many different enzymes.<ul> <li>Detect HRP in immunoassays</li> <li>Detect trace amounts of hydrogen peroxide (H₂O₂)</li> <li>Detect using fluorometer or microplate reader</li> <li>&lambda;_Ex/&lambda;_Em(pH 9)= 571/585 nm (end product)</li> <li>&epsilon;= 54,000 (end product)</li> <li>White to off-white solid soluble in DMSO or DMF</li> <li>Store desiccated at -20&deg;C and protect from light</li> <li>C₁₄H₁₁CNO₄</li> <li>MW: 257.24</li> <li>[119171-73-2]</li></ul>Amplex Red is a registered trademark of Thermo Fisher Scientific.