Abstract
Electron crystallography has recently gained attentions in multiple fields of research, as it has been demonstrated to determine atomic structures for inorganic, organic, and macromolecular materials from nano-sized crystals that were not amenable to conventional X-ray crystallography. Here, we demonstrate continuous-rotation microcrystal electron diffraction (microED) in a 200 kV transmission electron microscope using a DE-64 camera-a low-noise direct electron detector that can accommodate a linear response up to ∼1200 electrons per pixel per second at 20 fps with 2x-hardware-binning, making it ideal for acquisition of high-quality diffraction patterns. We have used this method and camera to determine a 0.75 Å structure of an organic molecule, biotin, with an exceptional goodness-of-fit, as well as a 0.88 Å structure of a chiral molecule, L-serine.