Protein-polysaccharide loss during endochondral ossification: immunochemical evidence.

Fluorescein labeled antibodies to protein- polysaccharides from rat and calf cartilage were used for the histochemical localization of protein- poly saccharide in epiphyseal cartilage. There was less protein- polysaccharide in the zone of provisional calcification than in the proliferating and maturing zones, and none was demonstrable in the metaphysis. During or just preceding cal cification, protein- polysaccharide or its protein component is lost or drastically altered.