PROJECT SUMMARY/ABSTRACT The Integrated Pathology Core (IPC) at the Oregon National Primate Research Center (ONPRC), major research center at Oregon Health & Science University (OHSU), requests funds for a Leica Stellaris 8 confocal microscope. The Stellaris 8 instrument will replace an aging Leica SP5 confocal, which has been in place since 2008, and does not meet current user needs such as multiplexing, live-cell imaging, scanning of large tissue areas such as the brain, and clarified thick sections. The new instrument's high resolution, sensitivity, and fast scan rates will increase both the quality and productivity of research at ONPRC. This instrument represents a significant technological advance, including a continuous-wavelength, tunable white-light laser, which provides up to 8 wavelengths from 440 to 790 nm, flexible spectral detection, TauSense technology, Acouso Optic Tunable Filter and Beam Splitter, and Power HyD detectors, all of which facilitate multiplex and live-cell imaging. The IPC, which is funded by the ONPRC P51 core grant, provides comprehensive, expert, and cost- effective advanced optical microscopy support to investigators by providing them access to state-of-the-art microscopy technologies that enhance collaborative, multidisciplinary research. Acquisition of this instrument will have a high impact on biomedical research at ONPRC and OHSU and will expand the scope of a wide spectrum of NIH-funded projects. Numerous NIH-funded projects will heavily utilize the Stellaris 8 confocal from all the ONPRC scientific divisions at ONPRC (Neuroscience, Pathobiology and Immunology, Reproductive and Developmental Sciences, Genetics, and Cardiometabolic Health). The instrument will be sited in the Advanced Optical Microscopy component of the IPC. ONPRC commits to ensuring long-term, efficient use of the instrument by covering costs of the service contract and Core staff salary via the P51 grant and as needed. Instrument time not used by the ONPRC investigators will be available to other scientists at ONPRC's host institution, Oregon Health & Science University (OHSU), and collaborating biomedical research entities. The introduction of this instrument will fulfill the growing needs of the biomedical research community at ONPRC and OHSU to incorporate state-of-the-art confocal microscopy into their research.