<br> <p>Gene expression analysis of DPPC populations by RT-PCR, at early PDs.  All DPPCs showed positive expression for the MSC markers, CD73, CD90 and CD105; and the absence of the hematopoietic marker, CD45.  All DPPCs analysed were also negative for hTERT.  Only low proliferative capacity DPPCs (A1, A2, B1, C2 and C3) were positive for the expression of CD271 (nerve growth factor receptor p75, LNGFR) and for all 3 senescence-associated marker genes analysed, p53, p21^waf1 and p16^INK4a.  Replacement of cDNA with H₂O served as negative controls, with β-actin serving as the reference housekeeping gene.</p>