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

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