International
Tables for
Crystallography
Volume F
Crystallography of biological macromolecules
Edited by E. Arnold, D. M. Himmel and M. G. Rossmann

International Tables for Crystallography (2012). Vol. F, ch. 9.1, p. 211   | 1 | 2 |

Section 9.1.2. The components of a monochromatic X-ray experiment

Z. Dautera* and K. S. Wilsonb

aNCI Frederick & Argonne National Laboratory, Building 202, Argonne, IL 60439, USA, and bYork Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5YW, England
Correspondence e-mail:  dauter@anl.gov

9.1.2. The components of a monochromatic X-ray experiment

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To collect X-ray data from single crystals, the following elements are required:

  • (1) a source of X-rays;

  • (2) optical elements to focus the X-rays onto the sample;

  • (3) a monochromator to select a single wavelength;

  • (4) a collimator to produce a beam of defined dimension;

  • (5) a shutter to limit the exposure of the sample to X-rays;

  • (6) a goniostat with associated sample holder to allow rotation of the crystal;

  • (7) the crystalline sample itself;

  • (8) a cryogenic cooling device for vitrified crystals;

  • (9) an efficient, generally 2D, detector system;

  • (10) software to control the experiment and store and display the X-ray images;

  • (11) data-processing software to extract intensities and associated standard uncertainties for the Bragg reflections in the images.

On a number of beamlines, automated procedures have been implemented for sample changing, automatic crystal centring, evaluating the diffraction and proposing a strategy for data collection. These allow rapid and more effective selection of the best sample and optimal parameters.

Many of these are discussed elsewhere in this volume. This chapter aims to provide guidance in those areas where choices are to be made by the experimenter and is concerned with the interrelations between parameters and how they conspire for or against different strategies of data collection.








































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