Figure 5

Morphology, growth characteristics, and telomerase activity of primary cell cultures. In P6 KCI-MENG1-LP cells, the spindle-shaped cells account for the majority the cell population (a). In contrast, the round cells become more predominant at P9 with much fewer spindle cells (b). At higher passages (c), KCI-MENG1-HP cultures are composed of exclusively round-shaped cells. This was also reflected in the growth curves of the low- vs. high passage cells (d). The P6 cells have a linear and shallow growth curve that was maintained for 96 h after cultures were seeded. P9 and P75 cells both demonstrated biphasic growth curves, with the shift in slope becoming apparent after 72 h (ANOVA p < 0.001). Likewise, the telomerase activity in P5 cells was very low, whereas it was very high in both P12 and P90 cells (ANOVA p < 0.0001) (e). Scale bar 50 µm.