‘Cool’ crystals: macromolecular cryocrystallography and radiation damage

Macromolecular crystals commonly suffer rapid radiation damage during room temperature X-ray data collection. Therefore, data are now routinely collected with the sample held at around 100K, significantly reducing secondary radiation damage, and usually resulting in higher resolution and better quality data. At synchrotron sources, the frequent observation of radiation damage even at cryotemperatures has prompted the development of exciting new experiments aimed at characterising and reducing this damage, and using it for structure determination and enzymatic studies. Current research into cryotechniques seeks to understand the basic physical and chemical processes involved in flash-cooling and radiation damage, which should eventually enable the rational optimisation of cryoprotocols.