Figure 2: Comparison of cell population doubling (PD) and colony forming efficiency (CFE) of human limbal epithelial cells cultured in SR and FAD media. (a) Human limbal epithelial cells were serially subcultured in SR medium and FAD medium for 10 passages (); cell population doublings (PD) number and accumulated PD were calculated and plotted. PD was calculated according to the following formula: , where represents the total number of cells obtained at each passage and represents the number of plating cells at the beginning of each passage. (b) To analyze the CFE, limbal epithelial cells were seeded at a density of 200 cells per 100 mm petri dish in SR and FAD media and allowed to grow for 12 days. (c) CFE values for epithelial cells in SR and FAD media were and , respectively. No differences of CFE were found between SR medium and FAD medium group (, ). (d) Percentage of colonized area in FAD was close to that of SR medium. The limbal epithelial cells maintained in SR medium exhibited similar CFE and colony size compared to cells maintained in FAD medium.