Figure 1. Characterisation of DPPC populations derived from human dental pulp tissues.

Characterisation of DPPC populations derived from human dental pulp tissues.  (A) Cumulative population doublings (PDs) were recorded for six DPPC populations during extended culture until senescence was reached, when PDs reached <0.5 PDs / week.  DPPCs A1, A2 and A3 were derived from patient A, while B1, C2 and C3 were derived from patients B and C, respectively.  Population A3 demonstrated high proliferative capacity, achieving >80 PDs over 280 days in culture, whilst the other DPPC populations only achieved 20-35 PDs over 35-85 days in culture.  (B) Telomere length analysis for the six DPPC populations at cited PDs, by Southern blotting.  Average telomere lengths were calculated using ImageJ^® Software.  Much longer telomeres were identified with high proliferative capacity, A3 (18.9 kb), compared with low proliferative capacity populations, A1 (5.9 kb), A2 (9.6 kb), B1 (5.6 kb), C2 (7.2 kb) and C3 (12.8 kb).  A3 (18.9 kb, 9 PDs) only exhibited equivalent telomere lengths to low proliferative capacity DPPCs, at much later PDs towards the end of its proliferative lifespan (6.4 kb, 55 PDs).  CTRL lane represent the separated DIG-labelled telomere length control.  Separated DIG-labelled telomere length standards are also included.