Journal of Synchrotron Radiation

Volume 13, Part 1 (January 2006)

research papers

J. Synchrotron Rad. (2006). 13, 30-45 [ doi:10.1107/S0909049505036721 ]

The Structural Biology Center 19ID undulator beamline: facility specifications and protein crystallographic results

G. Rosenbaum, R. W. Alkire, G. Evans, F. J. Rotella, K. Lazarski, R.-G. Zhang, S. L. Ginell, N. Duke, I. Naday, J. Lazarz, M. J. Molitsky, L. Keefe, J. Gonczy, L. Rock, R. Sanishvili, M. A. Walsh, E. Westbrook and A. Joachimiak

Abstract: The 19ID undulator beamline of the Structure Biology Center has been designed and built to take full advantage of the high flux, brilliance and quality of X-ray beams delivered by the Advanced Photon Source. The beamline optics are capable of delivering monochromatic X-rays with photon energies from 3.5 to 20 keV (3.5-0.6 Å wavelength) with fluxes up to 8-18 × 10¹² photons s^-1 (depending on photon energy) onto cryogenically cooled crystal samples. The size of the beam (full width at half-maximum) at the sample position can be varied from 2.2 mm × 1.0 mm (horizontal × vertical, unfocused) to 0.083 mm × 0.020 mm in its fully focused configuration. Specimen-to-detector distances of between 100 mm and 1500 mm can be used. The high flexibility, inherent in the design of the optics, coupled with a [kappa] -geometry goniometer and beamline control software allows optimal strategies to be adopted in protein crystallographic experiments, thus maximizing the chances of their success. A large-area mosaic 3 × 3 CCD detector allows high-quality diffraction data to be measured rapidly to the crystal diffraction limits. The beamline layout and the X-ray optical and endstation components are described in detail, and the results of representative crystallographic experiments are presented.

Keywords: X-ray beamline; protein crystallography; MAD/SAD; X-ray optics.