My laboratory studies various aspects of HIV science taking a cell biology approach. The centerpiece of our approach is microscopic imaging, which provides important information relating to context and dynamics of biological functions. To study HIV, the Hope lab has developed a series of techniques and tools that allow the fluorescent labeling of HIV particles or viral proteins and the identification of infected cells. We can now follow virions and infected cells from the tissue culture dish to whole animal models. For more than a decade we have combined this cell biology approach, supplemented with molecular biology, biochemistry, and genetics to study various aspects of HIV from virus entry and assembly, to defining the earliest steps of the sexual transmission of HIV. The studies to define the mechanisms of transmission have recently redirected a large aspect of the lab to HIV prevention science, including vaccine and microbicide research.