Assessing the applicability of a modified replication banding protocol for the analysis of radiation-induced chromosomal aberrations in cultured human lymphocytes

To analyze radiation-induced chromosomal aberrations in cultured human peripheral blood lymphocytes, a modified protocol for replication banding in combination with fluorescence in situ hybridization (FISH) using whole-chromosome-specific DNA probes was examined. The aim of the major modification of the experimental procedure was to efficiently generate clear and consistent replication bands along metaphase chromosomes in the first division of lymphocytes after culture initiation. This technique enabled the mapping of the sites of rearrangements directly on banded chromosomes at 400-550 band levels. On the basis of the characteristics of replication banding, the procedure described in the present study demonstrated the applicability for the analysis of gamma-ray-induced chromosomal aberrations in early- and late-replicating X chromosomes in cultured human peripheral blood lymphocytes.