The use of cationic cacodylate iron colloid for the histochemical staining of acid mucopolysaccharides in human submandibular gland.

Abstract

Both ferric hydroxide-cacodylate colloid (Fe-Cac) and a fine-grain one (Fe-Cac-f) are stable and carry positive charges over a wide range of pH. Using the colloid solution, some reliable information about the histochemical staining of acid mucopolysaccharides in human submandibular gland tissue could be obtained. Fe-Cac staining at pH 2 followed by Prussian blue reaction showed a diffuse blue staining of mucus acini, the intensity of which was equal to that of the staining at pH 4, clearly showing the sulfated mucopolysaccharides in the mucin. Most of serous acini were stained as blue granules in their cytoplasm. Fe-Cac-f staining gave a more distinct deep color by the Prussian blue reaction to the components, because of a superior diffusibility of the colloid into tissues. By Fe-Cac-f staining at pH 2 diffusely stained substances were found in the intercalated and striated ducts, showing the accumulation or passage of the secretions. The method will be useful for histochemical researchers in the oral field, in place of Alcian blue and its critical electrolyte concentration method.