Microscopy Methods for Imaging MIF and Its Interaction Partners.

Fluorescence microscopy has become a powerful tool to investigate proteins in their natural environment. Well-established techniques like widefield and confocal fluorescence microscopy have commonly been used for decades to visualize biomolecules in single cells and tissue sections. Live cell microscopy allows for the investigation of biomolecular trafficking, and other specialized techniques, such as proximity ligation assays (PLA) and fluorescence lifetime imaging microscopy (FLIM), can be used to study interactions between biomolecules of interest. Finally, with the most recent rise of optical super-resolution microscopy, we can investigate target biomolecules in situ with unprecedented detail on the nanometer scale. Here, we discuss various optical microscopy techniques that have successfully been used to image MIF. We highlight applications, advantages, and limitations of each technique. The techniques described here can easily be adapted to investigate other target proteins, their localization, interaction partners, and mechanisms of action.