Differences in Mechanism in Staining Reactions for Mast Cells

MAST cells are usually identified histochemically by the use of aldehyde fuchsin 1 , Hale 2 or Rinehart 3 stain, or by the metachromasia they exhibit with certain basic dyes. All these methods demonstrate mucopolysaccharides, although differences in the degree of staining of various mucopolysaccharides with the several methods have been noted 4 . Peracetic acid oxidation.(Greenspan's mixture 30 min., 25° C.) 5 of tissue sections has been found to induce staining of certain normally unreactive substances with aldehyde fuchsin 6–8 , and to alter the susceptibility of oxytalan fibres to hyaluronidase, lysozyme and elastase 7 . During the course of investigations of mucopolysaccharide reactivity after peracetic acid oxidation, an interesting change was observed in mast-cell cytoplasms. Peracetic acid oxidation followed by digestion with enzymes which hydrolyse mucopolysaccharides resulted in diverse staining reactions with the above three methods for mucopolysaccharides.