Metaphase arrest, anaphase recovery and aneuploidy induction in cultured Chinese hamster cells following exposure to mitotic arrestants.

Metaphases of Chinese hamster cells in culture, when blocked by mitotic arrestants, regardless of their mechanisms, would recover when a proper concentration was used. Arrested metaphases would quickly enter anaphase and karyokinesis ensued. However, the frequency of abnormal anaphases would increase when the period of arrest was prolonged, and the frequency of aneuploidy in the recovering cell generations would likewise increase. It appears that in the future, assays for aneuploidy induction by mitotic arrestants can be simplified by determining their potency of mitotic block without the tedious chromosome counts.