The success of an electron-microscopy analysis depends decisively on the quality of the specimen. A TEM sample should not exceed a thickness of 50–100 nm; for high-resolution TEM the limit is a few tens of nanometres. Suitable thin specimens of bulk materials can be prepared in the EMC-M laboratories mechanically as microtome sections, by ion-beam etching as a lamella, or by combined grinding and ion milling. A clean surface further avoids contamination and charging effects during imaging and improves the accuracy of spectroscopic analyses; for this purpose the sample can be treated with a plasma cleaner. For the native preparation of objects in aqueous environments, such as protein complexes, an automated cryo-plunger together with cryo-transfer holders is available. Suspended nanoparticles and powders can be dispersed onto the specimen support and dried using an ultrasonic sprayer.