Jean-Marc Strub2 Sylvie Luche1

A comparison between Sypro Ruby and ruthenium II tris (bathophenanthroline disulfonate) as fluorescent stains for protein detection in gels A comparison between two fluorescent metal chelates for staining proteins separated by electrophoresis has been carried out. One of these chelates is ruthenium II tris (bathophenanthroline disulfonate) and the other is commercial Sypro Ruby. Both can be efficiently detected either with UV tables or with commercial laser fluorescence scanners. The sensitivity and homogeneity of the stains and the interference with mass spectrometry analysis have been investigated. It appears that both stains per-form similarly for protein detection, while ruthenium II tris (bathophenanthroline disul-fonate) performs better for mass spectrometry analyses and as cost-effectiveness ratio. However, Sypro Ruby is easier to use as a stain