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BM14 was the first dedicated macromolecular crystallography (MX) beamline to come into operation at the ESRF during 1995. This experimental station has been designed specifically to produce MX diffraction data using Single/Multiple-wavelength Anomalous Diffraction (SAD/MAD) methods (www.bm14.eu). Currently, beamline is operated by a consortium between the ESRF, the EMBL-Grenoble and the Department of Biotechnology (DBT), India. Recently, the beamline optics was fully upgraded (hence the new denomination BM14-2). A four-time increase in beam brilliance is achieved with the concomitant reduction in average exposure time (~5s today versus 20s before), leading to a substantial gain in the screening capacity. Upgrade includes a new channel-cut crystal equipped with a second crystal pusher to reject high-energy harmonics. The latter device turned to be crucial for Sulphur-SAD experiment success rate. The special goniometer head is installed on microdiffractometer (MD2) goniometer which is capable of handling the CrystalDirect (CD) nanocrystallisation plates [1] so that any crystallisation hit can be exposed to the beam. The plate characteristics are optimal for in situ data collection and they produce diffraction patterns with significantly reduced background. A newly designed dehydration-to-cryogenic nozzle-changer device is also installed in order to avoid the down time between the experiments (such as, In situ screening, humidity control device (HC1), standard cryogenic data collection). European users may apply for access via the Biostruct-X program (www.biostruct-x.eu) both for CD plate nanocrystallisation trials and for beamtime. Users from India are encouraged to apply from DBT-Portal (http://process.mbu.iisc.ernet.in/BM14/index.jsp) for beamtime. The optics hutch refurbishment and implementation of the novel devices in the experimental hutch opens promising perspectives for collecting data at room temperature and that are of importance to the MX users.
abstracts
Bending Magnet beamline 14 (BM14) at the European Synchrotron Radiation Facility (ESRF, Grenoble, France) is dedicated to macromolecular crystallography (MX). This experimental station has been designed specifically to produce MX diffraction data using the methods of Single- or Multiple-wavelength Anomalous Diffraction (SAD or MAD) (www.bm14.eu). From 1994 to 2000, BM14 operated as an ESRF public beamline. Then from 2001 to 2009 the beamline was acquired and operated as an UK Medical Research Council Collaborative Research Group beamline. Since 2010, it is now back an ESRF beamline operated by a consortium between the ESRF, the EMBL Grenoble Outstation and the Indian Department of Biotechnology for the benefit of both the European and Indian MX communities. During 2011 and 2012, the beamline optics' hutch was fully upgraded (hence the new denomination BM14-2). As a consequence the upgrade produced a four-time increase in beam brilliance with the concomitant reduction in average exposure time (~5 s today versus 20 s for BM14), leading to a substantial gain in the beamline screening capacity and in scientific productivity. Moreover, in addition to the new optical elements, the new channel-cut crystal was equipped with a second crystal pusher to reject high-energy harmonics. This latter device turned to be crucial for sulphur-SAD experiment success rate as it is very efficient in "cleaning up" the spectral purity of the low energy beams. We will illustrate the benefit of rejecting harmonics in terms of data quality and phasing power, critical for S-SAD experiments. We will also explicit our multiple-kappa orientation approach to enhance multiplicity as well as to optimise scaling protocols, both also very important for the success rate of these very low anomalous signal experiments. Nota Bene: European users may apply for direct access to the beamline via the Biostruct-X European program (www.biostruct-x.eu). Users from India are encouraged to apply from http://process.mbu.iisc.ernet.in/BM14/index.jsp
