Method for separating a lamella for TEM inspection from a core sample

The invention relates to a method for slicing lamellae (5) from a core sample (1) and placing the lamellae on a TEM grid (6) for inspection in a TEM (Transmission Electron Microscope). Such a core sample may be a vitreous core sample formed by high-pressure freezing of biological material. Conventionally such lamellae are formed by slicing the lamellae from the core sample with a cryo-ultra-microtome. Due to the mechanical forces exerted on the vitreous material during the slicing artefacts occur, such as knife-marks, chatters, crevasses and deformation. By slicing the lamellae from the core sample by milling with a focused ion beam (4) no mechanical forces are exerted to the vitreous material, thereby eliminating these artefacts.