Figure 1: Morphological and flow cytometric characterization of primary human mesenchymal stem cells (hMSCs). (a) Morphology of primary human umbilical cord blood-derived MSC cultured in normal growth medium. hMSCs at passages 8-9 have a fibroblast-like morphology. ×100. (b) Immunophenotyping results of human umbilical cord blood-derived MSCs. Cells at passages 8-9 were stained with antibodies listed in Section 2 and assayed by flow cytometry. The cells were strongly positive for MSC-specific markers, such as CD13, CD44, CD73, CD90, and CD105, while negative for the hematopoietic stem cell markers CD14, CD34, and CD45. Staining for nonspecific immunoglobulin G (IgG) isotype fluorescence used as a control is represented by gray fill.