Diffraction Before Destruction: Outrunning Radiation Damage at the Femtosecond

X-ray crystallography is limited by radiation damage, which destroys macromolecular samples before any images can be collected, leaving some of our most important molecular structures unresolved in 3D. Free-electron lasers (XFELs) address this challenge with femtosecond X-ray pulses, enabling diffraction before destruction—an ultrafast photo taken before radiation damage can occur. Using a new time-resolved approach to serial femtosecond crystallography, we aim to outrun radiation damage in PSI microcrystals and capture the first light-activated structures of this protein complex that drives photosynthesis. With the newly developed Compact X-ray Free Electron Laser (CXFEL), this study asks: Can we take enough ultrafast photos to build models of PSI never seen before?