Three‐Dimensional Electron Microscopy

Abstract

In three‐dimensional electron microscopy (3DEM), nanoscale objects (eg, biological macromolecules) are reconstructed from data recorded with a transmission electron microscope that produces electron micrographs . These provide us with estimated 2D projections in which the grayness at each point is indicative of a line integral of a physical property of the object being imaged. From multiple‐electron micrographs, one can recover the structure of the biological object that is being imaged. In this article, two basic modes of data collection for 3DEM (namely, single particle and tomography) are discussed. This is followed by a presentation of computer algorithms for the reconstruction of a 3D object from its 2D projections; both transform methods (eg, filtered backprojection (FBP)) and series expansion methods (eg, the algebraic reconstruction techniques (ARTs)) are discussed. These are illustrated on one application, namely, 3DEM of influenza virus.