Molecular Horizons Seminar - Dr Hongyi Xu

X-Ray Diffraction (XRD) has been an indispensable tool in material science, structural chemistry, and structural biology. Despite the evolution in laboratory X-ray and synchrotron sources over the last few decades, a significant roadblock in the determination of molecular structures is the ability to grow crystals of sufficient size and quality. Crystal optimization can be time-consuming, complicated, requires a large amount of purified molecules, or even unfeasible for many biological macromolecules and pharmaceutical compounds. Three-Dimensional electron diffraction (3D ED), also known as Micro-crystal electron diffraction (MicroED), is an emerging and game-changing technique with the potential to overcome these challenges as it allows structure determination of crystals 1 billionth the volume of those used for SCXRD. 

Since 2007, 3D ED has allowed structure determination of landmark samples, mostly inorganic, that were considered impracticable for X-ray methods. Researchers from several labs have developed different experimental set-ups for data acquisitions, for example automated diffraction tomography (ADT, University of Mainz) and rotation electron diffraction (RED, Stockholm University). In 2013, Gonen’s lab successfully developed the MicroED technique for the determination of macromolecular crystal structures. However, 3D ED/MicroED is still in its infancy. Further development is required in order to unleash the full potential of 3D ED/MicroED applications in material science, structural chemistry and structural biology.