Characterization of human periodontal ligament stem cells (hPDLSCs) (A) As markers of mesenchymal stem cells (MSCs), CD13, CD34, CD90, and CD146 were used for fluorescence-activated cell sorting analysis of hPDLSCs. For whole-cell analysis of CD13-, CD34-, CD90-, and CD146-positive cells, the percentage of the cells positioned in the right side of the M1 gate was measured (n = 3) (B) To identify the multipotent lineage differentiation of hPDLSCs, cells were incubated with osteogenic (1 week for alkaline phosphatase [ALP] staining; 2 weeks for [Alizarin red S ARS] staining), adipogenic, and chondrogenic (3 weeks) induction medium (scale bar = 100 μm).