A combination of some clever ideas and trial and error over the years has since given rise to a collection of highly sensitive and effective protein gel staining techniques and products. These include the popular and reliable Coomassie Blue, a variety of silver staining techniques, the reversible, negative staining of gels with heavy metal salts, fluorescent dyes, and three lesser-known dyes with some interesting properties. Additionally, the use of colloidal gold sols to stain proteins on transfer membranes is well characterized and very useful. Finally, an automated gel staining machine is now on the market.
Silver staining is currently regarded as the most sensitive staining method, detecting as little as 1 nanogram of protein per band, compared to the 30 nanograms to 100 nanograms per band detected by Coomassie Blue staining methods (T.H. Steinberg et al., Analytical Biochemistry, 239:223-97, 1996). Proteins, however, can and do respond differently to silver staining. ...
