Abstract
A method for demonstrating acidic polysaccharides in formalin fixed parafin embedded tissue sections using fluorescein labelled deacetylated chitin is described. Epithelial and connective tissue acidic polysaccharides have been studied in a number of organs. The distribution of acidic polysaccharides as seen with fluorescein-labelled deacetylated chitin is similar to results obtained with alcian blue-periodic acid Schiff and fluorescein-labelled Aspergillus polysaccharide. Previously reported fluorescent staining methods for acidic polysaccharides such as iron-hematoxylin-acridine orange and atabrine as well as fluorescein-labelled deacetylated chitin may prove to be useful adjuncts to the light microscopic methods of demonstrating mucins. Other possible uses of deacetylated chitin, a colorless macro-cation, in histochemistry and cytochemistry are noted.