Serial crystallography

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Serial crystallography

Serial crystallography allows crystal structure determinations by recording diffraction still images from a few hundred to several thousand microcrystals in random orientations.
By typically using exposure times down to a few femtoseconds at X-ray Free electron Lasers (XFELs), serial crystallography is ideally suited for time-resolved measurements.
Data collection in SX ideally requires a high-intensity micro-focused X-ray beam. Thus, the experiments are ideally performed at latest generation synchrotron sources or at X-ray Free Electron Lasers (XFELs).Being based on the measurements of micro-crystals, , where a reaction in the crystals is triggered by laser excitation or by chemical mixing. The use of micro-crystals instead of measuring only one or a few relatively large single crystals, as done in conventional crystallography.
It is part of FS-BMX mission to further develop the method of SX with the goal to make it a well applicable and reliable method available to a broad user community from academia and industry. A major effort in this direction is the development of the Roadrunner goniometer, which has been developed for fixed target-serial crystallography. The Roadrunner goniometer is a very flexible and modular instrument consisting of 4 major units: The high-precision goniometer with the special feature of a high-speed scanning stage, a high-resolution on-axis sample viewing microscope for alignment and sample visualization, a capillary beamstop setup for experiments with ultra-low background scattering levels, and a measurement chamber providing an atmosphere with defined and controllable temperature and humidity. With it’s fast scanning axis it allows performing ultrafast fixed target serial crystallography experiments with sample exchange rates of up to 1 KHz (Tolsitkova 2019). At such data collection rates, complete intensity datasets for structure determination can be collected in a few seconds, which is similar what can be achieved in conventional crystallography.
For the measurements microcrystals are either loader or directly crystallized on the sample holders and then systematically raster-scanned through the X-ray beam [scientific reports 2015, Lieske 2019].
The Roadrunner goniometer has been used for experiments at different X-ray facilities wordwide already, including the Linac Coherent Light Source (LCLS) in Stanford, USA, the European Synchrotron Radiation facility (ESRF) in Grenoble, France, and is a standard installation at the European XFEL in Schenefeld, Germany.
More recently we have extended the Roadrunner goniometer to a flexible platform allowing performing different sample delivery methods such as liquid jets, highly viscous extruders, and a tape drive system.