Chapter

Chapter 11.2 Integration of macromolecular diffraction data

Crystallography of biological macromolecules

Second Online Edition (2012)

Part 11. Data processing

  1. A. G. W. Leslie

Published Online: 14 APR 2012

DOI: 10.1107/97809553602060000831

International Tables for Crystallography

International Tables for Crystallography

How to Cite

Leslie, A. G. W. 2012. Integration of macromolecular diffraction data. International Tables for Crystallography. F:11:11.2:266–271.

Author Information

  1. MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, England

Publication History

  1. Published Online: 14 APR 2012

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Abstract

In this chapter the integration of macromolecular diffraction data from two‐dimensional area detectors is described. Data integration refers to the process of obtaining estimates of diffracted intensities (and their standard deviations) from the raw images recorded by an X‐ray detector. When collecting data, a decision has to be taken about the magnitude of the angular rotation of the crystal during the recording of each image: the rotation per image can be comparable to, or greater than, the angular reflection range of a typical reflection (coarse ϕ slicing), or it can be much less than the reflection width (fine ϕ slicing). The latter approach allows the use of three‐dimensional profile fitting and, providing that the detector is relatively noise‐free, improves the quality of the resulting data by minimizing the contribution of the X‐ray background to the total measured intensity. Methods of integration are described and integration by simple summation and by profile fitting is discussed.

Keywords:

  • background;
  • data integration;
  • detector overloads;
  • errors;
  • integration of diffraction data;
  • outliers;
  • overloads;
  • partially recorded reflections;
  • profile fitting;
  • standard profiles;
  • summation integration