The ability of cells to polarize is crucial for development, wound healing, and neurotransmission. As many cellular polarity factors play central roles in disease (e.g. cancer, neurological dysfunction) understanding the molecular basis of cell polarity is of great importance to the biomedical sciences. One central aspect of cell polarity involves the regulation of the cytoskeleton and membrane-trafficking machinery, leading to the delivery of specific proteins and lipids to distinct cellular subdomains. This polarized membrane traffic seems important for cells that exhibit local cell growth, including migrating cells. Using advanced imaging approaches I showed that migrating cells preferentially deliver their secretory vesicles towards the leading edge (i.e. the front), and that this polarized delivery depends on intact microtubules (MTs). But how MTs and polarized membrane traffic contribute to cell migration remains unclear. Recent work on wound-edge migrating cells has identified factors that lead to distinct MT polarity phenotypes, i.e. MT stabilization and centrosome orientation, both of which could contribute to bias membrane traffic towards the front of the cell by either forming specialized vesicular tracks or by positioning secretory organelles in front of the nucleus. I will use interdisciplinary cell biological and state-of-the-art imaging and screening approaches to 1) investigate the mechanism of how MT polarity and polarized membrane traffic contribute to directed migration using known factors, 2) identify membrane trafficking factors that play a role in directed migration using automated image-based screening and 3) investigate the role of common traffic/migration factors in polarized membrane traffic and MT polarity. Further, I will implement ‘super-resolution’ microscopy to image the nanoscale localization of polarity factors in greater detail. These studies are aimed toward a more comprehensive understanding of cell polarity.