Growth characteristics of CHO cells in culture

The dependence of the growth characteristics and monolayer formation on the initial cell plating concentration were studied on a permanent CHO cell line. The cells were cultivated under standard conditions on plastic substrate. Initial plating concentrations were varied as 1000, 2000, 3000, 4000, 5000, and 6000 cells/cm2. It was shown that the cell growth can be formally described by a standard S-shaped dependence. However, a more detailed analysis revealed inconsistency of the experimental and expected data. Specifically, the cell growth termination produced by monolayer formation does not coincide with the time when the theoretical curves approach a plateau. It is concluded that cell proliferation and monolayer formation are independent processes (at least in CHO cells). Both processes may be considered as analogs of proliferation and morphogenesis in metazoa. In addition, it is shown that the cessation of cell division is induced by reduction in the cell size to some limiting dimension and increasing of the cell polarization rather than contact inhibition of proliferation after the monolayer formation.