Figure 1. Characterization of human tonsil mesenchymal stem cells (T-MSCs). Surface marker profiling determined by fluorescence-activated cell sorting in T-MSCs. The cells were positive for CD73 and CD44 and negative for CD45 and CD31; the upper panel is T-MSCs #1 and the lower panel is T-MSCs #2 (A). The adipogenesis, chondrogenesis, and osteogenesis of T-MSCs were examined by oil red staining, alizarin red staining, and Alcian blue staining, respectively; the upper panel is T-MSCs #1 and the lower panel is T-MSCs #2 (B).