The histochemistry of galactose residues of complex carbohydrates as studied by peroxidase-labeled Ricinus communis agglutinin.

A peroxidase-labeled Ricinus communis agglutinin diaminobenzidine (PO-RCA-DAB) procedure has been utilized to determine the light microscopic localization of galactose residues of complex carbohydrates in a variety of tissues from different vertebrate species. In the same tissues, the localization of mannose and glucose residues was studied by means of a concanavalin A peroxidase diaminobenzidine (Con A-PO-DAB) procedure for comparison. The distribution pattern of galactose residues was found to be in distinct contrast with that of mannose and glucose residues in connective and epithelial tissues such as those involved in the umbilical cord, cartilage, aorta, comb, thyroid gland, submaxillary gland, duodenum, jejunum, colon and gill of various vertebrates. The results of the present study indicate that the PO-RCA-DAB procedure is useful in providing a means of dividing periodic acid-Schiff reactive neutral complex carbohydrates into subgroups in comparison with the intensity of their Con A-PO-DAB reaction in the histochemistry of complex carbohydrates.