Fig. 2

EMCs maintain melanocytic phenotypes at 14 population doublings. A Flowcytometric analysis of EMCs and TMCs with antibodies against MelanA (red). Positive cells of EMCs were 91.49%, while TMCs were 91.52%. B Population doubling level of EMCs from the 20th to 38th passage. "Population doubling" indicates the cumulative number of divisions of the cell population. C Comparison of Doubling Time with EMCs (passage from 20 to 30) and TMCs (passage from 2 to 12). The doubling time averages were 22.3 days (± 11.45) and 14.2 days (± 15.20) in EMCs and TMCs, respectively. D Quantitative RT-PCR analysis of genes for MITF, Tyrosinase, TRP1, DCT, PAX3, and KIT at each passage. EMCs reached 14 population doublings at passage 21 (p21). The expression levels were normalized by expressions of GAPDH. The expression levels of EMC at passage 15 (p15) were regarded as equal to 1.0. Each expression level was calculated from the results of triplicate technical experiments and the charts are drawn as averages ± standard deviation. E Karyotype analysis in EMCs at passage 38. EMCs had normal karyotypes (46, XX)