In situ X-ray crystallography

A method is proposed, and preliminary experiments are described, for collection of X-ray data from macromolecular crystals in situ. The usual processes of mounting for either room-temperature or cryogenic X-ray data collection are eliminated by growing crystals, using vapor diffusion, on small supports or films that can be either frozen or treated before transfer directly to the X-ray beam. The approach has the advantage that individual crystals are never manipulated and it is not necessary to isolate single crystals. Furthermore, crystals fixed to the surface on which they grow provides a positive advantage, small and otherwise problematic crystals become serviceable, and robotic or automated data collection becomes simplified.