A new method for predetermining the diffraction quality of protein crystals: using SOAP as a selection tool
Acta Cryst. (2005). D61, 130–140
A polarising light microscope (the Metripol) is used to quantitatively assess the optical quality of crystals of three different proteins (HEWL, glucose isomerase and the 2F1-3F1 module pair of human fibronectin). By comparing variations in the slow optical axis position (SOAP) with indicators of diffraction quality [I
], it is shown that the optical properties of a protein crystal can provide a non-invasive method of predetermining likely crystal diffraction quality before X-ray data collection is undertaken.
R. L. Owen and E. Garman