Induction of high frequencies of endoreduplication in mammalian cell cultures with 33258 Hoechst and rubidazone.

Cells of the mouse L strain and the Chinese hamster CHO line were treated with 33258 Hoechst, rubidazone, and a combination of these. Recovering cell populations following the drug removal exhibited a high frequency (20--50%) of metaphases with diplochromosomes (endoreduplication), especially in the combination treatment series (up to more than 70% in the L strain). Such a procedure should be useful in probing the mechanisms of the endoreduplication process.