An alternative to DAB or as a second color for multiple antigen labeling, RedHRP substrates produce red reaction products. The sections stained with redHRP substrate need to be dehydrated, cleared, and permanently mounted in organic media. Red substrate provides excellent color contrast in pigmented tissue such as melanoma. With the aid of imaging systems and software, the spectral profile of AEC-derived substrates can be distinguished from otherHRP substrates in multiple antigens co-localization. This substrate can be used forHRP-conjugates such as antibodies on PVDF or nylon membranes but is not recommended for the use on nitrocellulose membranes in western blotting application.