Funds are requested to purchase a Zeiss Elyra S1 Super-Resolution fluorescent microscope. The Zeiss Elyra S1 is a 3D Structured Illumination Microscopy system that enables state-of-the-art imaging of subcellular structures. In contrast to conventional confocal and deconvolution microscopy, this system has advanced to such a degree that we can resolve multiple marked structures in multi-colors as never before. This technology doubles the previous maximum 250nm resolution and allows researchers to define the relationships between proteins that reside in adjacent compartments in three dimensions. This will substantially enhance our understanding of the structure of tissues, cellular organelles and higher order protein complexes. The instrument will support 6 NIH-funded major users and 5 minor users. While the majority of users are at The University of Arizona, Tucson, the instrument will be available as a regional resource. Data collected by the Zeiss Elyra S1 will be used to increase our understanding of heart and skeletal muscle function and dysfunction, cardiovascular and immune function, human infections, cellular alterations that lead to cancer and basic cell biology. Being able to resolve cells at this level will permit these investigators t push their research programs forward in unexpected and amazing ways.