A common immunohistochemical chromogen labelling and immunoblotting is 3,3’Diaminobenzidine (DAB). DAB forms a brown precipitate that is insoluble in alcohol when the peroxidase enzyme is present. This product must be mixed with a hydrogen peroxide-containing DAB substrate solution. Although the ratio can be changed as needed, the standard working dilution is 50ul (0.9 mg) of DAB Chromogen per 1ml of DAB Substrate. Using liquid components also eliminates waste that frequently arises from using tablets that have a set final volume and lowers some of the risks associated with handling powders, such as dust inhalation. The reagent is perfect for automated stainers because it can be used for up to six hours after the two ingredients are combined.