Improved investigative techniques including electron microscopy, isotope tracings and improved histochemistry have greatly increased knowledge of the function of cartilage as a body tissue. Highly complex and delicate enzyme systems contained in the cartilage cell are involved in cartilage matrix formation and in the processes of calcification and cartilage repair. Heat, various drugs, freezing, and changes in the chemical environment damage or destroy these enzyme systems and interfere with the growth and function of cartilage. Hyaline cartilage to be transplanted must be handled with great care to preserve the cellular enzyme systems-otherwise the graft will be resorbed and clinical failure will result.