Relocated chromosomes may require passage through mitosis to revert to distributions similar to control cells post cisplatin wash-off. Normal DNA-damage-dependent repositioning (A, B, I, J) and repair-dependent reversal (C, K) of chromosomes 12 (I, J, K), 17 (I, J, K) and 19 (A, B, C) in human dermal fibroblasts. In fibroblasts that were treated with cisplatin (25 μM) for 4 hours, and then allowed to repair in colchicine-containing media, the reversal of relocated chromosomes 12, 17 and 19 is not observed (F, N). Colchicine, by itself, has no effect on the positions of CTs 12, 17 and 19 (D, L) and on the forward relocation of these CTs after DNA damage (E, M). After removal of colchicine from the media, these relocated chromosomes revert back to locations similar to those of control cells (G, H). Chromosome 11 territories remain at the nuclear periphery under all these conditions (A- H). Scale bar: 10 μm.