Localization of chondromucoprotein in cartilage.

The histochemical localization of acid polysaccharides involves difficulties of fixation and usually reactions of uncertain specificity. Thus, the aqueous phase used in most fixatives is liable to elute at least part of the material, while most staining reactions lack specificity. The latter problem has lately been successfully attacked by the use of the salt-controlled alcian blue technique (Scott and Dorling, 1965). The present paper describes the application of an immuno-histochemical technique to this problem. Chondromucoprotein (CMP) in cartilage was detected by the application of antibody directed against this substance. The immunological characteristics of the reaction and nature of antigen and antibody have been fully described elsewhere (Loewi and Muir, 1965; Muir, 1958). Antiserum to CMP is predominantly directed against the protein part; for this reason parallel studies have been carried out with the alcian blue technique to demonstrate the acid polysaccharide part of the CMP complex.