Silver staining techniques

The second step in 2D electrophoresis is to separate proteins based on molecular weight using SDS-PAGE. Individual proteins are then visualized by Coomassie or silver staining techniques or by autoradiography. Because 2D gel electrophoresis separate proteins based on independent physical characteristics, it is a powerful means to resolve complex mixtures proteins (Fig. 2.1). Modem large-gel formats are reproducible and are the most common method for protein separation in proteomic studies. 

APES may interfere with silver salt solutions in intensification steps of immunogold silver-staining techniques therefore, for those applications, poly-L-lysine or gelatin-coated slides are preferable. 

Fomsgard, A., Freudenberg, M.A., Galanos, C. Modification of the silver staining technique to detect lipopolysaccharide in polyacrylamide gels. J Clin Microbiol 28 (1990) 2627-2631. 

Automatic and quantitative microscopes tend to give erroneous results for transparent particles. To overcome this problem Amor and Block [49] a silver staining technique to make the particles opaque. The particles are dry-mounted on to a thin film of tacky colloidon on a microscope slide. Silver is then deposited from solution using the silver mirror reaction. Preliminary sensitizing the crystalline surface ensures that much more silver is deposited on the particles than on the colloidon. A method of staining particles in aqueous solution prior to deposition on a membrane filter for analysis is also given. 

Studies of the antimicrobial and therapeutic properties of silver and its derivatives have yielded an extensive scientific literature, ranging from clinically- to biochemically-based papers. The latter area includes studies in enzymatic and other macromolecular interactions to silver resistance encompassing plasmid-mediated patterns. The reduction to one silver compound (AgSD) in the current British National Formulary and to two compounds (AgSD and silver nitrate ophthalmic solution) in USP XXII may not be a true reflection of the use of silver in health care today. Silver compounds also find use in non-clinical situations, for example, as water disinfectants and, not considered in this review, as silver staining techniques for microscopy. 

Kodama, Y.. Yoshida, M. C., and Sasaki, M. (1980). An improved silver staining technique for nucleolus organizer regions by using nylon cloth. Jpn. J. Hum. Genet. 25, 229-233. 

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