Synchronization of human lymphocyte cultures by fluorodeoxyuridine.

A simple technique for synchronization of human lymphocyte cultures with fluorodeoxyuridine (FudR) is presented. The S-phase block induced by the FudR is released by simultaneous exposure to 5-bromodeoxyuridine (BrdU) and Hoechst 33258 or by thymidine and Hoechst 33258. This method provides a high mitotic index with high percentage of prometaphase chromosomes. This simple method is highly advantageous and easy to utilize in clinical cytogenetics.