Three-dimensional Optical Microscopy of Biological Specimens

The ability to analyze biological specimens in three dimensions represents one of the major achievements of modern structural biology. For all but the simplest repeating structures, three-dimensional analysis is a crucial prerequisite for understanding complex biological assemblies. Near atomic resolution analysis of of crystalline proteins, nucleic acids, and viruses by X-ray crystallography approaches the routine. The current frontier focuses on the three dimensional analysis of non-crystalline, non-symmetric biological structures of cellular dimension. Electron microscope tomography and three dimensional optical microscopy are perhaps the most powerful methods for these studies.