Low-dose Chest CT Leaves DNA Intact (IMAGE) Radiological Society of North America Caption Immunofluorescent staining performed to depict γ-H2AX foci. Representative images of γ-H2AX foci in peripheral blood lymphocytes in an 82-year-old woman who underwent standard-dose CT. (a) Nuclear DNA of four lymphocytes. (b) γ-H2AX foci (arrows). (c) Markers of DNA double-strand breaks. In this merged image, DNA is blue and γ-H2AX foci are red (arrows show small foci). γ-H2AX, a marker of DNA double-strand breaks, is a phosphorylated type of histone H2AX. Scale bar: 5 mm. Credit Radiological Society of North America Usage Restrictions May use with credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.