Figure 1: Characteristics of isolated MSCs. (a) Flow cytometric analysis of MSC surface markers. The expression of surface antigens was plotted against appropriate IgG isotype controls (grey histogram). MSCs used for the analyses were positive for CD73, CD90, CD105, and CD166 and negative for CD14, CD34, CD45, and HLA-DR (clear histogram). (b) Mesenchymal differentiation potential of MSCs. The cells derived from MSCs expressed alkaline phosphatase activity, stained positively for lipid vacuoles with Oil red O, and were positive for chondrocyte matrix with toluidine blue, indicating osteogenic, adipogenic, and chondrogenic differentiation, respectively.