PubReading [196] - Radiation damage to biological samples: still a pertinent issue - E. Garman and M. Weik

<p>An understanding of <strong>radiation damage</strong> effects suffered by biological samples during structural analysis using both <strong>X-rays</strong> and electrons is pivotal to obtain reliable molecular models of imaged molecules. This special issue on radiation damage contains six papers reporting analyses of damage from a range of biophysical imaging techniques. For <strong>X-ray diffraction</strong>, an in-depth study of multi-crystal small-wedge data collection single-wavelength anomalous dispersion phasing protocols is presented, concluding that an absorbed dose of 5 MGy per crystal was optimal to allow reliable phasing. For small-angle X-ray scattering, experiments are reported that evaluate the efficacy of three <strong>radical scavengers</strong> using a protein designed to give a clear signature of damage in the form of a large conformational change upon the breakage of a disulfide bond. The use of X-rays to induce OH radicals from the radiolysis of water for <strong>X-ray footprinting</strong> are covered in two papers. In the first, new developments and the data collection pipeline at the NSLS-II high-throughput dedicated synchrotron beamline are described, and, in the second, the X-ray induced changes in three different proteins under aerobic and low-oxygen conditions are investigated and correlated with the absorbed dose. Studies in XFEL science are represented by a report on simulations of ultrafast dynamics in protic ionic liquids, and, lastly, a broad coverage of possible methods for dose efficiency improvement in modalities using electrons is presented.</p><p><em>doi.org/10.1107/S1600577521008845 - 2021</em></p>