 Alcian Blue has a relatively high solubility in salt solutions and stains slower than other dyes.By changing pH or ambient salt concentrations characteristic staining patterns can be obtained.At pH 1.0 it stains only sulfated polysaccharides and at pH 2.5 also stains carboxyl group containing sugars such as sialic acids and uronic acids intensify the stain of hyaluronic acids, which would also stain albeit relatively weakly by their half sulfate esters at pH 1.0.