Carmen Mannella is a Visiting Professor in the Dept of Physiology and Center for Biomedical Engineering and Technology of the University of Maryland School of Medicine, Baltimore MD. His research focus is the structure and permeability properties of mitochondrial membranes and their impact on bioenergetic function. His early research (at the Wadsworth Center in Albany NY) helped define the molecular structure of the gated channel in the mitochondrial outer membrane, VDAC, using biophysical and biochemical approaches including cryo-electron microscopy. Later, he turned his attention to the inner membrane and led the team that first applied electron microscopic (EM) tomography to the study of mitochondria. Tomograms revealed the complexity of the internal compartments (cristae) and how their morphology changed with physiological/pathological states, and with mutations in proteins involved in crista generation and ATP synthesis. As co/director of Wadsworth's national bioimaging resource center, he also led technology development and application in EM tomography, the use of focused ion beams to thin cryogenic specimens (now widely used), and time-resolved cryo-EM imaging of macromolecular complexes.