Fluorouracil synchronization of human bone marrow cultures. In vitro induction of high resolution R-banding by simultaneous exposure to 5-bromodeoxyuridine/Hoechst 33258.

A simple R-banding technique, based on a fluorouracil S-phase block, released by exposure to 5-bromodeoxyuridine and Hoechst 33258 is applied to human bone marrow cells. It is both simple and reliable, plus ensuring an index corresponding to that of the methotrexate method. Due to Hoechst 33258 exposure prior to harvest, chromosome contraction is partly inhibited. Well defined R-banding in elongated prometaphase chromosomes is observed both after traditional Giemsa and FPG-staining.