Silver Stains

In silver staining of protein gels, silver ions (such as from silver nitrate), bind to the negatively charged side chains of the amino acids. Once the excess silver ions are washed away, the remaining ions can be reduced to form a visible stain of metallic silver. This method of staining is highly sensitive and can be used to detect proteins down the nanogram amounts. Certain silver staining kits can even distinguish as little as 0.1 ng of protein. While silver has been known to be fairly incompatible with downstream mass spectroscopic analyses, many kits now feature MS-friendly silver staining reagents and workflows.