Use of ‘Nuclear Monolayers’ to Identify Factors Influencing DNA Double-Strand Breakage by X-rays

Abstract

Nuclear monolayers, prepared by treatment of mammalian cells with non-ionic detergents, showed increased sensitivity to X-ray-induced DNA double-strand breakage (dsb), as compared with intact cells, due to a decrease in the low-dose ‘shoulder’. The DNA dsb dose–response shoulder could be restored by irradiating nuclei in the presence of sulphydryl compounds. However, the ineffectiveness of glutathione, when used at near cellular levels, in restoring the shoulder, suggested a possible role for protein sulphydryls in the radiation response of intact cells.