Fig. 5. Effects of anti-MTf-antibodies on cell shape and proteoglycan synthesis by chondrocytes in the absence of ConA. (A) Poorly differentiated chondrocytes were incubated with 1% control serum, 1% pAb2-4, 100 µg ml^–1 control mouse IgG or 100 µg ml^–1 IgG purified from the pAb4 serum for 24 hours. (B) Poorly differentiated chondrocytes were incubated with the control serum or pAb4 serum at concentrations of 0.05-1% for 24 hours. (C) Poorly differentiated chondrocytes were incubated with 1% control serum or 1% pAb4 for 7 days. Bar, 30 µm. The values are averages ± s.d. for the four cultures. *P<0.01.