Silver-staining of proteins in polyacrylamide gels: a general overview

TL;DR

This paper reviews various silver-staining methods for proteins in polyacrylamide gels, comparing their sensitivity, reproducibility, and applicability, and discusses future directions for the technique.

Contribution

It provides a comprehensive overview of existing silver-staining protocols, introduces new methods for thin gels, and evaluates their performance and limitations.

Findings

Silver-diammine complex methods offer uniform sensitivity but require special gels.

Silver nitrate protocols are more versatile and broadly applicable.

Longer staining methods tend to be more sensitive and reproducible.

Abstract

On the basis of the physico-chemical principles underlying silver-staining of proteins, which are recalled in this paper, several methods of silver-staining of proteins after SDS electrophoresis in polyacrylamide gels or isoelectric focusing were tested. The most valuable protocols are presented in this report, including standard methods for unsupported gels and new methods devised for thin (0.5 mm) supported gels for SDS electrophoresis or isoelectric focusing and for staining of small peptides. Generally speaking, the most rapid methods were found to be less sensitive and less reproducible than more time-consuming ones. Among the long methods, those using silver-diammine complex gave the most uniform sensitivity. They require however special home-made gels and cannot be applied to several electrophoretic systems (e.g. systems using tricine or bicine as the trailing ion, or isoelectric focusing in immobilized pH gradients). For these reasons, protocols based on silver nitrate are of a more general use and might be favored. Future trends for silver-staining will also be discussed.