Abstract
Both aqueous and alcoholic variants of a periodic acid N,N-dimethyl-p-phenylenediamine method selectively impart color and fluorescence to neutral mucopolysaccharides. The aqueous method reveals differences in reactivity of various neutral polysaccharides. Prolonged staining of histologic sections with the aqueous variant superimposes a different coloration of acid mucins. This procedure offers advantages in differentiating periodate reactive from periodate negative acid mucopolysaccharides and in demonstrating mixtures of acid and neutral mucins in certain organs and cells.
Removal of basophilia by active methylation or sialidase digestion changes the periodate diamine staining of acid mucins to that characteristic of neutral mucins; sulfation of tissue sections induces the converse effect.