PROJECT SUMMARY Sanford Burnham Prebys (SBP) hosts labs with a very broad range of interests which include cancer, aging and age-related diseases like neurodegeneration, cell and tissue homeostasis and function, metabolism and stem cell biology. We truly believe that visualization of molecules of interest, using dyes or fluorophores, in the context of both their spatial and temporal location within cells or tissues is key to understanding physiological attributes of normal versus diseased states. Super-resolution microscopy has become a key technology in providing this context. However, an increase in spatial resolving power often requires a sacrifice in temporal resolution i.e. the speed at which molecular kinetics of fluorophores can be observed, which necessitates careful selection of the super-resolution mode required to fulfill experimental needs. For this purpose, SBP requests support for a Zeiss LSM980 with Airyscan 2. The LSM980 is capable of simultaneously imaging up to 4 different fluorophores with well-separated, non-overlapping emission spectra with a two-fold increase in spatial resolution. The Multiplex modes, only available on the LSM980, can speed up image acquisition up to twenty five-fold beyond acquisition rates on typical point-scanning confocal microscopes, and still provide a near two-fold increase in spatial resolution. This speed is essential in studying highly dynamic mechanisms that require higher spatial resolution, such as vesicular trafficking, transient molecular interactions or epigenetic changes. The ability to gauge subtle differences in these highly dynamic events will give our users a better grasp of molecular changes that occur from healthy to diseased systems. This speed of the Multiplex modes is also essential for fixed thick tissue imaging (>200µm) where large fields of view or thick slices can be imaged in a fraction of the time, at super-resolution. The LSM980 brings additional imaging benefits not currently available at SBP. The Quasar detector permits simultaneous imaging of the full emission spectrum i.e. all fluorophores. The LSM980 is more sensitive to weak samples and less sensitive to background noise, and the newly added Airyscan joint deconvolution processing provides 90nm spatial resolution. These features make it essential for projects requiring super-resolution imaging of thick samples, for e.g. organoids, cell clusters or drosophila embryos. As the LSM980 will be the first available for the San Diego community, the scientific advances made possible by acquisition of this instrument at SBP will allow the 12 major users with 75% of the accessible usage time (AUT) to generate previously unattainable data, which will further development of novel hypothesis, new funding and both internal and external collaborations.