*4.5. Flow Cytometry Analysis*

To examine c-kit expression, hCPCs were fixed in 4% PFA for 10 min and washed with PBS. The cells were fixed and permeabilized as previously described [50]. The fixed cells were incubated with c-kit antibody (#130-091-733, Miltenyi Biotec, Bergisch Gladbach, Germany) for 30 min at 4 °C. For expression analysis of other stem cell markers, hCPCs were suspended in 100 μL FACS buffer (2 mM EDTA, 2% FBS in PBS solution) and incubated with CD34 (#55373, BD Bioscience, Franklin Lakes, NJ, USA), CD45 (#560839, BD Bioscience, Franklin Lakes, NJ, USA), CD166 (#559263, BD Bioscience, Franklin Lakes, NJ, USA), CD29 (#555443, BD Bioscience, Franklin Lakes, NJ, USA), CD105 (#560829, BD Bioscience, Franklin Lakes, NJ, USA), and CD90 (#130-097-930, Miltenyi Biotec, Bergisch Gladbach, Germany) FACS antibody. After incubation for 30 min, the cells were washed three times and resuspended in 100 μL FACS buffer. Expression of stem cell markers was analyzed on a BD Accuri flow cytometer (BD Bioscience, Franklin Lakes, NJ, USA).
