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Updated: Aug 16, 2026

Protein Crystallization for X-ray Crystallography
Published on: January 16, 2011
A new method for predetermining the diffraction quality of protein crystals: using SOAP as a selection tool
Robin Leslie Owen1, Elspeth Garman
1Laboratory of Molecular Biophysics, Department of Biochemistry, Oxford University, Rex Richards Building, South Parks Road, Oxford OX1 3QU, England.
Abstract:
A microscope for quantitative analysis of the birefringence properties of samples is introduced. The microscope is used to measure variations in the slow optical axis position (SOAP) across hen egg-white lysozyme, glucose isomerase and fibronectin crystals. By comparing these variations with indicators of diffraction quality, it is shown that the optical properties of a protein crystal provide a non-invasive method of determining crystal diffraction quality before any X-ray data collection is attempted.
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