Alcian blue fixation allows silver staining of the isolated polysaccharide component of bacterial lipopolysaccharides in polyacrylamide gels

The effect of the cationic dye Alcian Blue on the silver staining of bacterial lipopolysaccharide and its polysaccharide and lipid A portions in polyacrylamide gels was investigated. The polysaccharide was only stained when the gel was previously treated with the dye. The polysaccharide moiety was found to be responsible for the lipopolysaccharide staining with silver, whereas the lipid A seemed unimportant. Treatment with Alcian Blue may prove useful to detect hydrophilic components of lipopolysaccharide samples that could not be stained by the usual silver staining procedures.