Multilineage differentiation assays of bone marrow-derived mesenchymal stem cells. After 3 weeks of pellet culture, mesenchymal stem cells (MSCs) maintained in the presence of transforming growth factor beta (TGF-β1) revealed strong chondrogenic induction as evidenced by strong staining with Alcian Blue, while controls without TGF-β1 were not chondrogenic (left panels). Monolayer cultures of MSCs responded equivalently to culture with osteogenic medium for 2 weeks in terms of strong staining for alkaline phosphatase (ALP) and matrix mineralisation with Alizarin Red as opposed to the weak staining revealed by the negative controls (middle panels). Adipogenesis was observed after 2 weeks of monolayer culture in adipogenic media by staining with Oil Red O for lipid droplets, while only negative staining was detected in the respective control cultures (right panels).
Steinert et al. Arthritis Research & Therapy 2012 14:R168 doi:10.1186/ar3921