Alkaline phosphatase activity, calcium deposition and nestin expression during osteogenic differentiation of human MSCs. A. Representative wells demonstrating the effects of time in osteogenic media on alkaline phosphatase activity (ALP) and calcium deposition (Alizarin red staining; AR). B. Effects of time in osteogenic media on Nestin expression in hMSCs. Bars represent mean nestin expression normalized to ribosomal protein L13 ± SEM relative to day 0 (n = 5).