Small-angle X-ray scattering (SAXS) measurements of proteins in solution are becoming increasingly popular with biochemists and structural biologists owing to the presence of dedicated high-throughput beamlines at synchrotron sources. As part of the ESRF Upgrade program a dedicated instrument for performing SAXS from biological macromolecules in solution (BioSAXS) has been installed at the renovated BM29 location. The optics hutch has been equipped with new optical components of which the two principal elements are a fixed-exit double multilayer monochromator and a 1.1 m-long toroidal mirror. These new dedicated optics give improved beam characteristics (compared with the previous set-up on ID14-3) regarding the energy tunability, flux and focusing at the detector plane leading to reduced parasitic scattering and an extended s-range. User experiments on the beamline have been successfully carried out since June 2012. A description of the new BioSAXS beamline and the set-up characteristics are presented together with examples of obtained data.

Small-angle X-ray scattering (SAXS) of macromolecules in solution is in increasing demand by an ever more diverse research community, both academic and industrial. To better serve user needs, and to allow automated and high-throughput operation, a sample changer (BioSAXS Sample Changer) that is able to perform unattended measurements of up to several hundred samples per day has been developed. The Sample Changer is able to handle and expose sample volumes of down to 5 ml with a measurement/cleaning cycle of under 1 min. The samples are stored in standard 96-well plates and the data are collected in a vacuum-mounted capillary with automated positioning of the solution in the X-ray beam. Fast and efficient capillary cleaning avoids cross-contamination and ensures reproducibility of the measurements. Independent temperature control for the well storage and for the measurement capillary allows the samples to be kept cool while still collecting data at physiological temperatures. The Sample Changer has been installed at three major thirdgeneration synchrotrons: on the BM29 beamline at the European Synchrotron Radiation Facility (ESRF), the P12 beamline at the PETRA-III synchrotron (EMBL@PETRA-III) and the I22/B21 beamlines at Diamond Light Source, with the latter being the first commercial unit supplied by Bruker ASC.

Dehydration of protein crystals is rarely used, despite being a post-crystallization method that is useful for the improvement of crystal diffraction properties, as it is difficult to reproduce and monitor. A novel device for hydration control of macromolecular crystals in a standard data-collection environment has been developed. The device delivers an air stream of precise relative humidity that can be used to alter the amount of water in macromolecular crystals. The device can be rapidly installed and is fully compatible with most standard synchrotron X-ray beamlines. Samples are mounted in cryoloops and the progress of dehydration can be monitored both optically and by the acquisition of diffraction images. Once the optimal hydration level has been obtained, cryocooling is easy to achieve by hand or by using a sample changer. The device has been thoroughly tested on several ESRF beamlines and is available to users.

A standard sample holder and vial for cryocooled macromolecular crystals has been defined for use with robotic sample changers. This SPINE standard sample holder is a modified version, with added features and specifications, of sample holders in common use. In particular, the SPINE standard meets the precision required for automatic sample exchange and includes a cap that is identified by a two-dimensional datamatrix code as well as an optional vial. At the ESRF, the sample holder standard is in use with the EMBL/ESRF/BM14 robotic sample changer (SC3) which is installed on eight beamlines. The SC3 can hold up to 50 crystals stored in five baskets. A datamatrix reader in the SC3 ensures safe management of the sample flow and facilitates fully automatic screening and characterization of samples. Tools for handling and transporting 50 samples in a dry shipping dewar have been developed. In addition to the SC3, the SPINE sample holder is currently compatible with a number of other robotic sample changers.

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C274 study, the apohost of 2 was determined from the laboratory powder X-ray diffraction data and the structural change by guest sorption and release processes were investigated. The powder X-ray diffraction data of the toluene inclusion crystal of 2 and the apohost crystal of 2, which was obtained by heating of the toluene inclusion crystal, are signifi cantly different as shown in the fi gure. However, interestingly, the apohost structure, determined from the laboratory powder X-ray diffraction data, was found to retain its crystal packing even after the guest release. The apohost has one dimensional stacking of 2 along the b-axis forming the one dimensional guest free tunnel. This tunnel is expected to absorb the guest molecules easily and, in fact, the apohost crystal readily absorbs the toluene molecules, when the toluene vapor was applied to the solid apohost, and it transforms into the toluene inclusion crystal within 20 min.

Poster Sessions C274 study, the apohost of 2 was determined from the laboratory powder X-ray diffraction data and the structural change by guest sorption and release processes were investigated.The powder X-ray diffraction data of the toluene inclusion crystal of 2 and the apohost crystal of 2, which was obtained by heating of the toluene inclusion crystal, are signifi cantly different as shown in the fi gure. However, interestingly, the apohost structure, determined from the laboratory powder X-ray diffraction data, was found to retain its crystal packing even after the guest release. The apohost has one dimensional stacking of 2 along the b-axis forming the one dimensional guest free tunnel. This tunnel is expected to absorb the guest molecules easily and, in fact, the apohost crystal readily absorbs the toluene molecules, when the toluene vapor was applied to the solid apohost, and it transforms into the toluene inclusion crystal within 20 min.[1] N. Iwasawa, H. Takahagi, J. Am. Chem. Soc., 2007, 129, 7754-7755 Keywords: ab-initio powder structure determination, solid-state transformation, macrocyclic compound MS11.P01Acta Cryst. (2011) Introduction of the new generation sample changer on the recently rebuilt BioSAXS ID14-3 beamline at the ESRF together with the implementation of 1M Pilatus detector have sensibly boosted its highthroughput capacities. The sample changer developed in collaboration between the ESRF and the EMBL (Grenoble and Hamburg outstations) automates the entire cycle of sample loading-unloading-cell cleaning and can hold up to several hundred of samples in micro-plates, eppendorf strips (PCR) or tubes. Thermal control, smart pipetting and sample positioning together with other features allow to run completely automated data collection without any user intervention through the dedicated beamline software, BsxCuBE. The user just needs to enter sample information (name, concentration, location in sample changer, etc.) and collection parameters (exposure time, temperature, fl ow during exposure, etc.). Afterwards the script performs data collection in the most economical and safe manner, processes 1D curves and fi lters them according to the radiation damage. It is followed by automated processing pipeline (developed by EMBL Hamburg) which analyses 1D curves and gives structural properties of the proteins (molecular sizes and ab-initio models). Reliable and simple-to-use sample environment together with robust software allow to perform easily and effi ciently the SAXS experiments even by non-experienced users.