Horseradish Peroxidase (HRP)

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Horseradish Peroxidase (HRP)

Horseradish peroxidase (HRP) is the most widely used enzyme for IHC labeling. The mechanism of HRP is such that an enzyme-substrate complex is formed between HRP and excess hydrogen peroxide (H2O2). In the presence of a chromogen, the oxidized product of this reaction polymerizes to yield a color specific to the chromogen itself.
Commonly used chromogens with HRP include:
  • 3-amino-9-ethylcarbazole (AEC)
  • 3,3’-diaminobenzidine (DAB)