Data Processing in Macromolecular Crystallography

Data processing in macromolecular crystallography is the effort by which a user converts a set of raw diffraction data into a list of Bragg reflections with measured intensities. With modern crystallographic hardware the raw data consists of a set of two- dimensional detector images, each collected at a particular orientation of the crystal. Data processing may be broken down into four steps: calibration, determination of the unit cell, measurement of the integrated intensities, and merging and scaling the integrated data. Algorithms for each of these steps have been derived and validated, and are implemented in several commercially available software packages. In recent years these packages have become more flexible and easier to use. Software developed for monochromatic laboratory experiments must be modified or even replaced when the user is performing more exotic experiments, particularly Laue diffraction experiments.