Simplified method for silver staining of proteins in polyacrylamide gels and the mechanism of silver staining

TLDR

The authors developed a simple, reliable silver staining method that requires only a few stable solutions and works on all gel types, including SDS‑polyacrylamide and isoelectric focusing gels. The method works on gels from 0.1–0.2 mm to 3 mm thick, relying on the gel’s redox properties to drive the staining reaction. The method detects proteins and polypeptides as small as 2500 Da with high sensitivity, and sensitivity depends more on protein structure than on gel type.

Abstract

Abstract The study of effects of several parameters on silver staining of proteins has led to the development of a staining method which is simple and reliable, requires only few stable solutions, and can be applied to all gel types such as sodium dodecyl sulfate (SDS) containing polyacrylamide or isoelectric focusing gels. It can be used for ultrathin layers (0.1–0.2 mm) or thicker slab gels (up to 3 mm). With this method not only proteins but also polypeptides of molecular weights as low as 2500 are detectable with high sensitivity. Comparison of isoelectric focusing and SDS‐containing gels and a simple spot test on thin gellayers show that the detection sensitivity depends not so much on the type of proteins but rather on their structure. The redox properties of the gel are important for the staining mechanism.