Lectin binding sites of glycoproteins as revealed by lectin-gold-silver and lectin-peroxidase-diaminobenzidine...

For the precise histochemical detection of lectin binding sites of glycoproteins, the results obtained by lectin-gold-silver (LT-G-S) staining methods have been systematically compared with those revealed by alternative techniques of lectin-peroxidase-diaminobenzidine (LT-PO-DAB) reactions in a series of organs from different mammalian species. Ricinus communis agglutinin-I and concanavalin A were the lectins used in the present study. In the tissues subjected to the LT-G-S procedures, reactive tissue structures exhibited positive reactions of varying intensities of black. The results of control staining for the LT-G-S methods substantiated the view that the reaction products demonstrated the precise lectin binding sites of glycoproteins. The staining images obtained by the LT-PO-DAB techniques were not necessarily correlated precisely with those revealed by the LT-G-S procedures, and unavoidable background staining in pale brownish shades was noted in the majority of LT-G-S negative tissue structures. In view of these results, the LT-G-S staining methods employed in the present study are believed to be a reliable technique for the precise localization of saccharide residues of glycoproteins in light microscopy.