This service provides sample preparation by plunge-freezing, grid clipping for autoloader system and cryo-TEM imaging at 200 kV. User can either provide the purified sample in solution, the sample already vitrified on EM grid, or the vitrified sample on an already clipped (i.e. Thermo Scientific autoloader compatible) EM grid. User might request cryo-EM screening on a maximum of 4 different samples per application. For each sample, a maximum of 3 Cryo-EM Screening sessions can be allocated. For each Cryo-EM screening session a maximum of 8 grids can be prepared and processed. An optional “polishing” SEC step can be performed on thawed material by the Biophysics Unit, as and if considered necessary by NF Staff. Glow discharging will be performed by either a Pelco EasyGlow, a Quorum GloQube, or Solarus II plasma cleaner device. Plunge-freezing will be performed on a Thermo Scientific Vitrobot Mk IV or a Leica EM GP2. Applicants may provide TEM grid supports of preference, otherwise NF staff will use holey TEM grid supports available. Imaging will be provided for a maximum of 8 continuous hours per unit of service. In case of grids showing optimal particle distribution and ice quality, this service can be extended for overnight data collection, if compatible with NF staff working hours. Cryo-TEM imaging will be performed only in EF-TEM mode at 200 kV on a Thermo Scientific Glacios equipped with a Falcon 4i direct electron detector and Selectris X energy filter. Imaging conditions requested by the User, if provided, must be compatible with NF practices. In case of User-provided already-clipped grids, these will be inspected by NF staff prior to acceptance. This service will only be performed by NF staff. This service does not cover for buffer screening (i.e. detergents, pH, salt, additives screening or else) or any other grid modifications (i.e. graphene oxide, pegylation, affinity grids or else).