DEMONSTRATION OF REPLICATION PATTERNS ON HISTONE-DEPLETED CHROMOSOMES

A modified immunologic technique is described for the purpose of demonstrating replication patterns on mammalian chromosomes after partial histone depletion. Replication patterns were induced by BrdU substitution and visualized by BrdU antibodies, coupled with peroxidase (diaminobenzidine/H2O2) or immunogold-detection. The replication patterns obtained by this technique did not reveal any additional details of replication compared to those shown by conventional cytogenetic staining. However, the possibility of demonstrating replication patterns on these partially histone-depleted chromosomes may prove useful for chromosomal in situ hybridization studies since the chromosomes produced are considerably larger than those seen in conventional preparations.