Chromogenic Detection
Chromogenic (also know as colorimetric) detection employs chromogenic substrates, which can be either alcohol insoluble – appropriate for Western blot and IHC, or alcohol soluble dyes – suitable for ELISA. The blot is incubated with a chromogenic substrate to yield a colored precipitation. Signal development is arrested by washing off the substrate. Resulting precipitate is visualized directly on a membrane as a band or a dot.
Chromogenic substrates are available for various enzymes: HRP (horseradish peroxidase), ALP (Alkaline phosphatase), GOD (Glucose oxidase) and β-Gal (β galactosidase).