[Study of human chromosome reproduction time using 5-bromdeoxyuridine]

5-Bromodeoxyuridine (BDU) -- 20 gamma/ml, 5-fluorodeoxyuridine (FDU) -- 0.1 gamma/ml and uridine -- 3 gamma/ml were introduced into the lymphocyte cultures of the peripheral blood of normal persons of both sexes. Chromosome preparations were prepared in 5 hours they were stained after the incubation in the fluorochrome solution Hoechstt 33258 with a 2% Giemsa solution on phosphate buffer (pH -- 5.0). Chromosome areas with incorporated BDU stained with Giensa solution but weakly; because of this regions with late replication were seen in each chromosome in thr form of weakly stained segments. A picture of late DNA replication is described on the basis of this method in all human chromosomes.