Growth potential and senescence features during long-term culture of UCMSC.

<p>A. At early passages (P3), UCMSC displayed a fibroblast-like morphology. B. With cell aging (P18), UCMSC became larger in size, with a more spindle-shape and flattened appearance. C. Average cell size of UCMSC in suspension measured using a confocal microscope at P3, P9 and P18. D. Growth kinetics of long-term cultured UCMSC. Cumulative population doubling (Y-axis left) is plotted against culture passage. Percentage of UCMSC staining positive for SA-β-gal (Y-axis right) at successive passages. E. SA-β-gal staining remained almost stable during early culture passages but increased significantly between P15 and P21.