*CALL FOR PROPOSALS FOR ESRF BEAM TIME WITH ONLINE MICROSPEC*Proposal
Deadline *4th September 2012*
There will be beam time available at the ESRF for MX data collection
with a setup that allows online monitoring of UV/VIS absorbance or
fluorescence spectral changes of the crystal during the X-ray
diffraction experiment. These complementary techniques will aid in the
interpretation of X-ray data in the context of reaction intermediate
state trapping and/or radiation damage monitoring, most particularly in
the case of redox or photoactive proteins.
Users who are interested in using this beam time (including those who
are members of BAG Groups) should use the
following mechanism:_http://www.esrf.fr/UsersAndScience/UserGuide/Applying/ProposalGuidelines/MXnon-BAGproposal
_and *it must be clearly indicated in the title of the proposal form
that the online monitoring of spectral changes is necessary for the
project*.A brief description of the device is given below however users
are encouraged to consult the web pages for detailed
information:_http://www.esrf.fr/UsersAndScience/Experiments/MX/How_to_use_our_beamlines/Run_Your_Experiment/Microspectrophotometer_User_Guide_The
device is also described in: McGeehan, J., Ravelli, R.B., Murray, J.W.,
Owen, R.L., Cipriani, F., McSweeney, S., Weik, M. and Garman,
E.F. (2009) Colouring cryo-cooled crystals: online
microspectrophotometry. /J.Synchrotron Radiat./ *16*, 163-172.
As this is not a standard set-up, it might take a significant amount
of time to train users, align the device, and analyze the data in order
to derive relevant data collection schemes. *We will therefore schedule
24 hours for each project*. The *deadline *for this specific application
is *Tuesday 4th September 2012*.
It is strongly recommended to, beforehand, record an
absorption (fluorescence) spectrum of the crystal on a home
microspectrophotometer such as the 4dx one, or at an off-line facility
such as the ESRF Cryobench, and to provide it in the application form.
Such a spectrum would greatly help to determine the feasibility of the
experiment. For optimal experimental conditions, crystals should be
flash-cooled in minimal amounts of cryosolution, especially when the
crystals are small. Finally, please note that *the ESRF sample changer
cannot be operated at the same time as the on-line microspec*. The use
of a specific laser is possible if the device is compliant with the beam
line safety system (interlock on device power).
Recent examples of research using the ESRF online microspectrophotometer
include: de la Mora /et al./ /Acta Cryst. D/ (2012), Ferraroni et al.,
/J. Inorg. Biochem./ (2012), Gumiero /et al./ /J. Biol. Chem./ (2011),
Hersleth /et al./ /Biochim. Biophys. Acta/(2011), Kiontke /et al./ /EMBO
J./ (2011), Orru et al., /J. Biol. Chem./(2011), Regis-Faro et al., /J.
Am. Chem. Soc./(2011)
++++++++++++
Dates of beam-time: *4th October - 7th October 2012*
Storage Ring: 7/8 +1 (200mA)
Beamline: ID14-1
Energy: 13.27 keV (not tunable)
Specifications:
UV/VIS-range: 250-1100 nm
Light source: Mikropack DH-2000-BAL (Deuterium/Halogen)
Fluorescence/Actinic excitation wavelength: 405, 440, 473, 532, 561, 671 nm
ODmax for UV-vis absorbance spectra: 2-2.5
Monitoring light size: 0.03 (min) - 0.15mm(max)
Sampling freq (to disk): 10Hz or lower
--
Dr David FLOT
Beam-Line Operation Manager Tel : (+33) 4 76 88 17 63
Structural Biology Group Fax : (+33) 4 76 88 26 24
ESRF
B.P. 220, 6 rue Jules Horowitz e-mail : david.f...@esrf.fr
F-38043 GRENOBLE CEDEX http://www.esrf.eu
