CD133+ gallbladder carcinoma cells exhibit self-renewal ability and tumorigenicity

Figure 5 Spheroid-colony-formation assay of CD133⁺ cells. Sphere-forming cells were isolated by fluorescence-activated cell sorting for marker CD133 and cultured in 96-well plates in serum-free medium (10 cells per well) containing human epidermal growth factor (20 ng/mL) and basic fibroblast growth factor (10 ng/mL). After 2 wk, the total number of spheroid colonies containing more than 20 cells was counted. CD133⁺ cells generated more spheroid colonies. ^bP < 0.01.