The overall mission of our research program is to understand the structure and function of complex biological assemblies by combining novel technologies for 3D biological imaging with advanced methods for image segmentation and computational analysis. We take an interdisciplinary approach to this problem, using emerging technologies in cryo-electron microscopy as our primary tool. Members of our group work on different, yet, complementary aspects of structural analysis. Key areas of current and future focus are:(i) the development and application of novel technologies for three-dimensional electron microscopy of specimens ranging in size from small molecules to tissues, (ii) determination of the dynamic architectures of cellular structures involved in cell division and chemotaxis in bacterial systems, (iii) determination of the atomic structures of membrane receptors, multiprotein complexes and nanoparticles using high resolution electron microscopy, and (iv) determination of the 3D structure, mechanisms of neutralization and cellular entry of HIVThe nature of our work requires expertise in areas spanning from cell and molecular biology to computational biology, physics and engineering. The research background of members in our team reflects this interdisciplinary mix, and we also benefit greatly from collaborations with a variety of scientists both inside and outside NIH.