A nitrous acid procedure as a selective histochemical means of eliminating the N-sulphates of glycoconjugates

Summary A nitrous acid procedure has been shown to lead to the elimination of N-sulphates in sections of a series of tissues containing sulphated glycoconjugates. Two groups of sulphated glycoconjugate-containing tissues were used; one contained N-sulphates and other was devoid of such groupings. In the first group of tissues, mast cells of different origins and renal glomeruli in the rat were employed. Xiphoid and tracheal cartilage matrix, submandibular and sublingual gland acini and gastric, duodenal and colonic mucosae were used in the second group. Sections were treated with nitrous acid and then stained with Alcian Blue pH 1.0, high iron diamine or Aldehyde Fuchsin for sulphated glycoconjugates. Such treatment was found to diminish the staining intensities exclusively in N-sulphated glycoconjugate-containing structures such as mast cell granules and renal glomerular basement membrane, providing a means of chemically eliminating N-sulphates of glycoconjugates in tissues.