electron microscopy Electron cryomicroscopy MI:0040 PSI-MI Electron microscopy methods provide insights into the structure of biological macromolecules and their supramolecular assemblies. Resolution is on average around 10 Angstroms but can reach the atomic level when the samples analysed are 2D crystals. Different types of samples can be analysed by electron microscopy: crystals, single particles like viruses, macromolecular complexes or entire cells and tissue sections. Samples can be chemically fixed or vitrified by rapid freezing in liquid ethane, and then transferred into the electron microscope. Data collection consists of the recording of electron diffraction data (2D crystals) and images. Depending on the type of sample, different approaches are used to analyse and merge images and electron diffraction data. Electron crystallography imaging technique