The effect of various decalcifying agents on cartilage proteoglycans.

Mineralized and unmineralized cartilages were treated with various decalcifying solutions to investigate proteoglycan loss after decalcification. Five percent formic acid decalcifies quickly and causes only minimal loss of uronic acid from calcified cartilage which cannot be appreciated by histochemical means. On the basis of our findings formic acid should be considered an excellent decalcifying agent for proteoglycan histochemistry in paraffin embedded cartilage.