Painter R B, Mathur V
Mutat Res. 1984 Mar;139(3):123-6. doi: 10.1016/0165-7992(84)90006-x.
Induction of sister-chromatid exchanges (SCEs) by ultraviolet light at 2.6 J/m2 in Chinese hamster ovary cells was significantly inhibited by pretreatment with 3 and 5 Gy of X-rays. No inhibition was observed when cells were treated first with ultraviolet light and subsequently X-irradiated with 5 Gy.