The effect of BMP-2 on the osteogenic expression in primary-derived cells. Osteogenic gene expression was examined in primary BMSCs (dot-dashed line), primary myoblasts (straight line) and primary fibroblasts (dotted line) using qPCR and data normalized to the housekeeping gene Gapdh. Ap expression was measured as an early osteogenic marker in cells cultured in the absence (A) or the presence (B) of BMP-2. Ocn expression was measured as a late osteogenic marker in cells grown in the absence (C) or the presence (D) of BMP-2. In addition, dose- and cell-dependent effect of BMP-2 on AP activity after 6 days (E) and mineralized nodule formation after 12 days (F) was measured in all three cell lines. Scale bar = 100 μm.