Macromolecular X-ray structure determination using weak, single-wavelength anomalous data
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Updated: Apr 19, 2026

Sample Preparation and Transfer Protocol for In-Vacuum Long-Wavelength Crystallography on Beamline I23 at Diamond Light Source
Published on: April 23, 2021
Gábor Bunkóczi1, Airlie J McCoy1, Nathaniel Echols2
1Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK.
Abstract:
We describe a likelihood-based method for determining the substructure of anomalously scattering atoms in macromolecular crystals that allows successful structure determination by single-wavelength anomalous diffraction (SAD) X-ray analysis with weak anomalous signal. With the use of partial models and electron density maps in searches for anomalously scattering atoms, testing of alternative values of parameters and parallelized automated model-building, this method has the potential to extend the applicability of the SAD method in challenging cases.
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