Phenotypic analysis of human adipose-derived stem cells. A and B, Flow cytometry depicting the diffuse expression of CD90 and CD44 stromal markers. C and D, Immunofluorescence staining revealing the strong expression of CD44 and CD90 in cultured ASCs. Nuclei are stained with Hoechst. Scale bar, 50 μm E, Phase contrast micrograph shows the typical elongated shape of adipose-derived stem cells in serum cultures. Scale bar, 150 μm F, Transmission electron microscopy image showing adipose-derived stem cell with the presence of intracytoplasmic lipid droplet electron dense (arrow heads). Scale bar, 10 μm.