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"Spinning, Poynting, Translating: Shining Light on a TIRF Field in Order to Visualize HIV Assembly", Monday, February 1, 1:00pm, MH 606
Daniel Johnson, Rockefeller University
ABSTRACT: Total Internal Reflection Fluorescence (TIRF) Microscopy is an illumination technique in which fluorophores near a microscope cover glass (within ~100 nm) are excited, while those further away from the cover glass are not. This selective illumination typically reduces noise compared to traditional microscopy methods, thus making it easier to study single biomolecule complexes, such as individual proteins, nucleic acids and viruses. In addition, TIRF illumination has a unique polarization geometry enabling excitation of fluorophores aligned perpendicular to the cover glass surface, which is particularly useful for studying cell membranes. Here a novel TIRF illuminator will be described which enables visualization of structural changes in HIV particles throughout assembly in living cells, and observation of viral particle scission from the cell membrane following formation. In addition, the recruitment timing (hijacking) of cellular factors necessary for virus scission will be presented. Quantifying these processes provides insight into how HIV forms and leaves a cell, leading to the eventual invasion of another host. Interrupting this process may be an important factor in reducing the spread of HIV.