Concanavalin A-peroxidase-diaminobenzidine-periodic acid-m-aminophenol-fast black salt K: a method for the dual staining of neutral complex carbohydrates.

A method has been developed for the dual staining of neutral complex carbohydrates in light microscopy. It combines a concanavalin A-peroxidase-diaminobenzidine (Con A-PO-DAB) method with a period acid-m-aminophenol-Fast Black salt K (PA-AP-FBK) sequence. With the combined method it is possible to stain alpha-D-glycosyl and alpha-D-mannosyl residues brown and 1,2-glycol groups of neutral complex carbohydrates blackish purple. The validity of the method has been confirmed with appropriate histochemical controls and enzyme digestions on test tissues.