Cryo Focussed Ion beam (Cryo-FIB)*

Cryo-electron tomography of structures inside thick cells requires the preparation of thin lamella, which are thin enough to be used in cryoET. Cryo-FIB milling is the method of choice to prepare these lamella. To prepare the lamella, cryo-EM samples are exposed to a focussed ion beam to remove the parts of the sample outside the area of interest until only the thin lamella remains. The resulting lamella can then be used in further high-resolution imaging. Most systems use a beam of focused Gallium ions to achieve the FIB milling.