About the mechanism of interference of silver staining with peptide mass spectrometry

摘要

The mechanism by which silver staining of proteins in polyacrylamide gelsinterferes with mass spectrometry of peptides produced by proteolysis has beeninvestigated. It was demonstrated that this interference increases with timebetween silver staining and gel processing, although the silver image isconstant. This suggested an important role of the formaldehyde used in silverstaining development in this interference process. Consequently, aformaldehyde-free staining protocol has been devised, using carbohydrazide asthe developing agent. This protocol showed much increased peptide coverage andretained the sensitivity of silver staining. These results were howeverobtained at the expense of an increased background in the stained gels and of areduced staining homogeneity.