SFX: A UK/European user consortium for a serial femtosecond crystallography beamline at the European X-ray Free Electron Laser.

The UK is building a dedicated user facility at the European X-ray Free Electron Laser (XFEL) in Hamburg to let British scientists fire ultra-bright X-ray pulses at tiny protein crystals before they are destroyed by radiation. Current synchrotron light sources require large, well-ordered crystals to determine the atomic structure of biological molecules. Many important targets—membrane proteins, viral complexes, and large molecular machines—refuse to form such crystals. XFELs solve this by using pulses so short (femtoseconds) that they outrun radiation damage, allowing data to be collected from crystals thousands of times smaller than conventional methods require. The XFEL also enables time-resolved studies that capture structural changes on the sub-picosecond timescale, potentially revealing how proteins actually function rather than just their static shapes. If successful, this infrastructure will enfranchise the UK structural biology community—among Europe’s strongest—in a technology that could ultimately image single particles like viruses without any crystals at all. The immediate impact is on fundamental science: understanding the atomic machinery of the cell. Over 33,000 structures have been solved in the last five years using third-generation sources; this project aims to accelerate that progress by removing a key bottleneck. A UK Hub at Diamond Light Source will handle sample preparation and triage to maximise efficient use of the XFEL beamtime.