Q-RT-PCR validation of differentially expressed genes. (a) Comparison of relative expression levels of mRNA for the genes indicated by Q-RT-PCR on unamplified RNA (black bars) and Affymetrix microarray data (gray bars) (n = 3). Samples were normalized using Gapdh as the housekeeping gene and percent expression level was calculated with respect to the highest-expressing sample. The asterisk (*) indicates genes evaluated in mMSCs grown in the MAPC condition. (b) Relative mRNA expression levels of Ecats and other ESC-expressed transcripts in mMAPCs (black bars) and ESCs (gray bars) quantified using Q-RT-PCR. Three independent isolations of mMAPCs and ESC RNA for Q-RT-PCR were used to confirm microarray mRNA expression results. Samples were normalized to ESC expression levels and Gapdh mRNA levels were used for internal normalization.