Ultrastructure of epiphyseal cartilage after extraction on thin sections of "Epon" of proteoglycans by calcium chloride]

Dissociative methods are commonly used to extract proteoglycans. With a 2 M CaCl2 solution these components can be also extracted from thin sections of fixed, "Epon" included material. Secretory granules of the chondrocytes, granular components of extracellular matrix as matrix vesicles lost their electron density. Glycoproteins of the cell coat as non collagenous glycoproteins disappear. The method seems to be valuable for extracting proteoglycans from thin sections prepared for electron microscope investigations.