Chromogenic detection for western blot, IHC, and ELISA

Chromogenic substrates can be used in a number of immunohistochemical applications from staining tissue with IHC through to Western blotting. The chromogenic substrate is added to a blot or tissue previously incubated with an enzyme-conjugated antibody (typically horseradish peroxidase (HRP) or alkaline phosphatase (AP)), which converts the substrate to a colored precipitate. Colorimetric detection is easy to use, although it may require optimization or additional staining to improve signal over background in samples expressing low antigen.