Expression of stem cell markers. mRNA isolated from ChDPSCs was used for RT-PCR analysis. The expression of stem cell (Nanog, Rex-1, Oct-4) and differentiation (Osteonectin, Osteocalcin, Osteopontin) markers was detected. Bone sialoprotein was not detected in ChDPSCs. Internal control: GAPDH. Negative control: water. All primers were designed to cross the junction between two exons with the upstream primer located at the 3'region of the leading exon; whereas, the down stream primer was located at the 5'region of the following exon in order to minimize the possibility of a false positive or contamination of genomic DNA.