Visualization of Protein

Chemiluminescence is the most widely used detection system in Western blotting. In chemiluminescence detection, an enzyme-linked secondary antibody is used to convert a substrate to one that produces light emission. The light emission is detected on a charge-coupled device (CCD) camera or photographic film.

The Western blot result is considered semi-quantitative—meaning it provides a relative comparison of protein levels, not an absolute measure of quantity.