PROJECT SUMMARY This shared instrumentation grant is for funds to purchase a Leica Stellaris confocal microscope to be housed in the Magee-Womens Research Institute. The MWRI confocal core serves the 70 basic- and clinical-research faculty who are full or affiliate members of MWRI. Currently, the MWRI core is comprised of a 10-year-old Nikon A1r with PMT detectors and resonant scanning and a nearly 20-year-old Leica SP2 confocal. The former has been maintained continuously under a service contract and was upgraded to steady-state lasers in 2015. The SP2, on the other hand, is at the end of its viable lifetime: it cannot be upgraded; it no longer has a functioning DAPI laser; vendor service contracts have been discontinued; and repair parts are difficult to attain. This application requests funds to replace the obsolete SP2 system with Leica's newest confocal, Stellaris, which was released this spring. Over the past ten years, innovations in confocal microscopy have improved sensitivity and resolution, decreased bleaching, and expanded fluorescent range. The new instrumentation will allow NIH-funded researchers to use state-of-the art imaging approaches to address a myriad of issues related to women's and reproductive health, including ovarian cancer etiology, meiotic crossover regulation, pelvic floor disorders, and placenta dysfunction, among others. Critically, the new system will allow users to achieve sub-diffraction imaging that is becoming a standard in the field and will enhance the live-imaging capabilities of the MWRI core. The recent hiring of faculty with confocal-intensive projects, together with expanded need of our user base, have made it difficult to support the confocal needs of the MWRI constituency with our current, outdated machine.