X-ray free electron laser single-particle analysis for biological systems.

The X-ray free electron laser (XFEL) is a new light source that can produce coherent, ultra-brilliant, femtosecond X-ray pulses. This X-ray beam provides new possibilities for studies in structural biology. In this review, we survey the applications of XFEL to biological systems, with an emphasis on studies of noncrystalline samples. Although atomic-level modeling is not yet achievable, this method enables high-throughput, damage-free imaging of biological samples under near-physiological conditions and is being rapidly developed. Here, we provide overviews of XFEL technology, experimental techniques, and computational data analyses, and discuss examples of such studies.