Electron tomography is applicable to in situ observations on plastic-embedded cells or tissue as well as to isolated particulates (usually under cryo-EM conditions or negatively stained). As such, it promises to revolutionize the role of electron microscopy in virology, cell biology, and related disciplines by providing 3D information of pleiomorphic structures (such as organelles, cytoskeleton, asymmetrical viruses, etc.). In electron tomography, it is necessary to record tilt series of 60-180 digital electron images of the same specimen, incrementally rotated trough angles of 1-3 degrees between successive exposures, while keeping the specimen centered in the field of view and consistently focused. In cryo-electron tomography, in which the technique is applied to specimens preserved in vitreous ice, series have to be recorded in a fashion that adequately preserves structures against radiation damage.
Below is a tilt-series of spherical silica cores with adherent gold particles.
With the purchase of the FEI T20 microscope and the necessary software for microscope control, 3D reconstruction, and visualization, all the necessary tools for tomography are available in the EML. To develop the technology into a cost-recovery service, the EML is developing an efficient workflow and performs personnel training in data acquisition and 3D reconstruction, as well as in segmentation of final tomograms.