Cryo-electron tomography of biological specimens

Abstract

Cryo-electron tomography (CET) is an imaging technique capable of visualizing the three-dimensional (3-D) structure of complex viruses, cells, and tissues in hydrated state. With the current resolution of 4-5 nm, CET can resolve supramolecular complexes that are responsible for many cellular functions. This paper discusses the important considerations in CET of biological specimens and identify areas where digital signal processing can make a decisive contribution. Topics discussed include the principles of electron tomography and CET, image background and feature contrasts in CET, acquisition and alignment of projection images, reconstruction of the image volume, denoising and segmentation of tomograms, and feature recognition in cellular tomograms.