Fig. 3From: Optimization of human umbilical cord blood-derived mesenchymal stem cell isolation and culture methods in serum- and xeno-free conditionsCellular senescence in UCB-MSC population at passage 2 (P2), 3 (P3), 4 (P4), and 5 (P5). The cells positive with β-galactosidase activity were indicated by arrows. Bar = 50 µmBack to article page