| Method |
Electron cryotomography is an emerging technique that allows the structures of unique biological objects such as individual macromolecules, viruses, and even small whole cells to be reconstructed in their near-native states in three dimensions (3-D) to an approximate 5-nm resolution. In cryo-electromicroscopy the specimen is cooled to cryogenic (very cool, under 123 Kelvin) temperatures, without fixing or staining it in any way. This is said to prevent the deformations which may be caused in non physiological conditions by other techniques such as in x ray crystallography. Cryo-electron tomography (CET) is a version of cryo-electron microscopy where a 3D reconstruction of a sample is created from tilted 2D images, again at cryogenic temperatures (either liquid nitrogen or helium). |