3,3'-Diaminobenzidine (DAB) is the most commonly used chromogen for demonstrating the presence of horseradish peroxidase in immunohistochemistry or immunoblotting. It produces a stable water/alcohol insoluble reddish brown product. This effect is enhanced by modifying the DAB solution with the addition of metal ions to produce a more dense reaction forming a localized deep blue/black precipitate.1,2 MP's Metal enhanced DAB Kit is a stable solution developed to give enhanced color reaction with low background.