Recent developments in microdiffraction on protein crystals

Protein crystallography microdiffraction and micro small-angle X-ray scattering at a 3(rd) generation synchrotron radiation source undulator beamline both require a compromise on beam size and beam divergence. Micro small-angle X-ray scattering requires in addition an as close as possible angular approach to the direct beam, which is mainly limited by the beam divergence at the sample position. Both techniques have been developed at the ESRF microfocus beamline in a complimentary way. The development of a dedicated microgoniometer in the frame of an EMBL/ESRF collaboration has revealed the potential of microdiffraction for protein crystallography and is a step in the quest for user friendly instrumentation.