Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Purpose: To study the effects of carbon K ultrasoft X-rays, which produce a single photoelectron with a track length of < 7 nm, on the production of structural chromosome-type changes. Materials and methods: Untransformed human fibroblasts (HF12) were irradiated in G1 phase. Aberrations were analysed using fluorescence in situ hybridization using multi-coloured chromosome specific DNA probes for chromosomes 1 and 2 and an α-satellite pan-centromeric probe. Results: C(K) X-rays have a high efficiency per unit absorbed dose for producing simple and complex exchanges. Mean absorbed doses of 0.33-1.31 Gy produce simple exchanges with a predominantly linear dose dependency, and visibly complex exchanges increased by more than the power 2 of the dose, with no evidence of a linear component. The proportion of exchanges that are visibly complex ranged from 9% to 46%. Conclusions: The linear response for simple exchanges provides further support to the hypothesis that damaged DNA may be able to interact with undamaged DNA. The high proportion of complex exchanges may be due to the increased efficiency of double-strand break induction and to the high density of tracks per unit absorbed dose targeting pre-existing sites, some of which may be close to the incident nuclear membrane.

Original publication




Journal article


International Journal of Radiation Biology

Publication Date





591 - 598