This service is designed to cover imaging on large volumes and includes sample preparation by either high-pressure freezing or chemical fixation, freeze substitution, resin embedding, section preparation by ultramicrotomy and S\TEM imaging at 300kV. The User can provide specimen already fixed, stained, embedded as well as already sectioned and made ready for EM acquisition. A maximum of 1 specimen can be processed per unit of service, and 4 samples maximum (i.e., replicates) can be prepared per specimen. High-pressure freezing will be performed on a Leica EM ICE. Freeze substitution will be performed on a Leica AFS2, and a User might specify a substitution protocol of preference, which will be utilized if compatible with Facility practices. Similarly, for chemical fixation, the User is allowed to specify their protocol of preference, which will be adopted if compatible with Facility practices. For resin-embedding, the User could provide a resin of preference, or alternatively, the currently available resin be used. Sections of resin-embedded sample will be prepared on Leica UC7. A maximum of 1 resin-embedded sample can be processed for unit of service, to be sectioned in ribbons, and to be applied to a maximum of 4 TEM support grids. User might specify thickness of final sections, and these recommendations will be followed if compatible with the Facility practices. User might provide TEM grid support of preference, otherwise the currently available grid support will be used. Imaging will be performed an a Thermo Scientific Spectra 300 kV either in TEM, equipped with CETA 2 camera, or STEM mode in BF\DF\HAADF. Imaging conditions, if requested by the Usermust be compatible with Facility practices. Microscope access is granted for a maximum of 5 days per unit of service, including all steps from sample loading to alignments and collection, and according to Facility Staff availability. All steps of this service will only be performed by Facility Staff. To maximise efficient use and access to high-end TEM instruments, priority will be given to applicants specifically requesting parts of this service (e.g. only sectioning, or only S\TEM imaging of already prepared sections).