ADAPTATION OF THE MOREL SISLEY PROTEIN DIAZOTIZATION PROCEDURE TO THE HISTOCHEMICAL DEMONSTRATION OF PROTEIN BOUND TYROSINE

Abstract

Protein diazotization followed by alkaline coupling with a naphthol has been successfully applied for the histochemical localization of the protein bound tyrosine in tissues. Prolonged nitrous acid treatment in the cold is required (18-24 hours at 3°C). The best coupling reagent so far tried is 1-amimio-8-naphthol-4-sulfonic acid (S acid) and coupling succeeds best in a 1 % potassium hydroxide in 70 % alcohol, allowing 1 to 4 hours at 3°C. Topochemical results parallel those of the Millon reactions, with greater color intensities and superior histologic definition.