Electron microscopy has allowed biologists to image ultrastructural elements of the cell. This standard technology is limited by the requirement that sample thickness be very fine. Since many of the cellular elements are asymmetric, these slice images provide only limited information. Electron Microscope Tomography (EMT) will allow the 3-dimensional reconstruction of electron microscope images of cellular ultrastructure objects. The sample thickness will extend up to 1 micrometer and resolution will be on the order of 50 Angstroms. Computer processing of image information similar to that employed in CAT scan technology will be used to reconstruct tilted projections. The 3-D reconstructions should provide greater understanding of the structure, and therefore the function, of cellular ultrastructural objects.
