Cryo-electron microscopy (cryo-EM) is a revolutionizing technique used to determine the structures of biological molecules. The sample is frozen in a thin layer of vitreous ice and imaged in an electron microscope. The method allows imaging a large range of biological molecules such as small proteins in nano-meter scale as well as large macromolecular complexes like filamentous assemblies at highest resolution. Moreover, even entire viruses, prokaryotic and eukaryotic cells can be visualized in near-native frozen-hydrated state.
