DNA organization affects cellular radiosensitivity and detection of initial DNA strand breaks

There is now considerable evidence indicating that DNA organization in the nucleus plays an important role in DNA damage and repair. Differences in DNA packaging can affect the ability to accurately quantify initial amounts of DNA single and double-strand breaks. It is possible that measurement of initial DNA damage using assays such as neutral filter elution and nucleoid-based methods may be used, perhaps in combination with assays of DNA repair capacity, as an indication of intrinsic cellular radiosensitivity. What is still unknown is how DNA packaging in the living cell affects DNA repair. Structural differences may alter the nature of the damage, the function/positioning of repair enzymes, influence induction of repair systems, or alter the recovery of higher order DNA structure. (author)