Molecules and their chemical interactions lie at the heart of the world around us. To understand biology, physics, and materials science on the molecular scale, Professor Biteen has been building super-resolution microscopes that bridge the gap between traditional microscopy and the nanometer scale of molecules. These new methods allow direct visualization of very subtle details—down to just one protein moving inside a living cell! Professor Biteen will discuss how this single-molecule fluorescence imaging can measure properties that have remained inaccessible due to the fundamental limitations of traditional approaches, with an emphasis on questions important to human health, for instance, “How do the bacteria in our guts ensure digestive health?” and "How is the cholera disease regulated?"