We offer sample preparation by negative stain EM followed by TEM imaging at 120 kV. A maximum of 4 service units (i.e. 4 days of screening and sample preparation on 1 specimen or 4 different ones) can be requested. For each session a maximum of 8 grids can be prepared and processed. Imaging will be provided for a maximum of 8 continuous hours per unit of service. An optional “polishing” size-exclusion chromatography (SEC) step can be performed on thawed material by the Biophysics Unit, as and if considered necessary by NF Staff. 400 mesh copper grids with amorphous carbon film layer will be used as support. Glow discharging will be performed by a Pelco EasyGlow device. Staining will be performed with a 2% (w/v) uranyl acetate aqueous solution. Imaging in TEM mode at 120 kV will be performed on a Thermo Scientific Talos L120C equipped with CETA 16M camera. Imaging conditions requested by the User, if provided, must be compatible with NF practices. This service will only be performed by NF staff.