Wednesday 14 December 2011
'Beam On' at ISIS
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Xpress beam time is becoming an increasingly popular service amongst ISIS users. Running for the past four years, the Xpress service offers users the opportunity to run test experiments or check sample quality before applying for a full beam time proposal.
Scientists send their samples by courier to ISIS, for measurements using specific neutron and muon techniques. The results are then processed and sent back. One of the major benefits of using the Xpress service is the speed and efficiency of the process. Results are obtained quickly and users do not need to write a proposal to apply for beam time, making the process much faster. So far there are six Xpress services covering a range of measurements from small-angle scattering to high-resolution spectroscopy.
Professor Gordon Roberts from the Department of Biochemistry at the University of Leicester and Professor Richard Hoogenboom from the Department of Organic Chemistry at Ghent University in Belgium have both been highly satisfied with the ISIS Xpress service. Both users said that applying for Xpress beam time was very easy and they would definitely consider using it again.
Gordon Roberts and his group were interested in domain movement in the flavoprotein cytochrome P450 reductase, a membrane bound enzyme required for electron transfer. Studying the system using X-ray diffraction, they suspected that the flavins were being reduced by X-ray-induced photoelectrons.
“Using neutron scattering provided the only definitive way of establishing whether this was the case,” said Roberts. “We were anxious to get results quickly, since they would determine not only our interpretation of previous results but also the future direction of our research programme.”
Using SANS Xpress, his group obtained a clear demonstration that their suspicions were correct. Although this work will need to be followed up with additional SANS experiments at ISIS, Professor Roberts is very hopeful that it will lead to a major publication.
Richard Hoogenboom used the SANS Xpress service to study polymers in solution, in order to understand their chain conformation. Having used SANS Xpress three times before, he says: “It is a fast and easy way to explore the potential of SANS for a certain problem, in particular for non-experts like me. Very important for me is the excellent support from ISIS with regard to interpretation and modelling of the data.” The results of his Xpress experiments have led to two publications.
Hoogenboom, R et al. (2009) Self-assembly of double hydrophobic block copolymers in water–ethanol mixtures: from micelles to thermoresponsive micellar gels, Chem Comm., 5582-5584.
Bloksma, M.M., Rogers, S., Schubert, U.S., Hoogenboom, R. (2010), Secondary structure formation of main-chain chiral poly(2-oxazoline)s in solution, Soft Matter, 6: 994-1003
For more information on the ISIS Xpress service see: http://www.isis.stfc.ac.uk/apply-for-beamtime/apply-for-beamtime2117.html
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