<unk>  is the name of two similar triphenylmethane dyes that were developed for use in the textile industry but are now commonly used for staining proteins in analytical biochemistry.<unk>  G-250 differs from<unk>  R-250 by the addition of two methyl groups. The name<unk> " is a registered trademark of Imperial Chemical Industries.
Coomassie brilliant blue
Azo dye
Lactophenol cotton blue
Metacresol purple
Hemichrome
Prussian blue 
Cresyl violet
Infracyanine green