Automated sample-scanning methods for radiation damage mitigation and diffraction-based centering of macromolecular crystals

Two sample-scanning features have been implemented for the macromolecular crystallography beamlines at APS sector 23: automated diffraction-based rastering employing multiple polygon-shaped two-dimensional grids overlaid on a sample to locate and center small and invisible crystals or to find the best-diffracting regions in a larger crystal, and automated data collection along a three-dimensional vector to mitigate the effects of radiation damage.