Differentiation of fetal MSCs from into adipocytes, osteocytes, and chondrocytes.

First-trimester fetal blood (9⁺² weeks; A-C), fetal liver (14⁺⁰ weeks; D-F), and fetal bone marrow (11⁺²weeks; G-I) into adipocytes, osteocytes, and chondrocytes. Adipogenic differentiation was indicated by accumulation of neutral lipid vacuoles that stained with Oil-red-O (A, D, and G, × 400 magnification), and such changes were not evident with human foreskin fibroblasts (J). Osteogenic differentiation was indicated by calcium deposition (B, E, and H, × 400 magnification), which stained with silver nitrate; this was not seen in foreskin fibroblasts (K). Chondrogenic differentiation was shown by staining with a monoclonal antibody to type 2 collagen and by the formation of lacunae (C, F, and I, × 400 magnification), not seen by similarly culturing human foreskin fibroblasts (L), which also produce collagen type 2.