Fig. 6.
Chondroblast differentiation from MPCs.
MPCs were trypsinized and cultured in expansion medium without serum, EGF, or PDGF-BB, but with 100 ng/mL TGF-β1 in micromass culture. For micromass cultures, 1 × 106 MPCs were diluted in 1 mL culture medium and added to a 15-mL conical tube, where close cell-cell interaction was induced. Differentiation to chondroblasts was shown by toluidine blue staining and positive staining for type II collagen but not type I collagen (A; enlargement = 10 ×). Presence of type II collagen was confirmed by Western blot on day 14 (B; clones nos. 1, 2, and 3; see also Figure 12; β-actin serves as loading control). A representative example of more than 5 experiments is shown.
