Analysis of the stem cell marker gene expressions based on quantitative RT-PCR. (A) Expression scores were obtained by the delta-delta Ct calculation method. All values are mean ± S.D. of 5 samples of SP (S) and NSP (N), and 6 samples of precultured SP (cS) and precultured NSP (cN). Significant differences were observed using ANOVA and Tukey's multiple comparison tests. Asterisks on bars indicate significant differences (P < 0.05). (B) Gel electrophoresis pattern recognition of real-time PCR products. Total RNA without reverse transcribed samples (RT-) were used as negative control.