A. Project Summary We are requesting funds to purchase a new Nikon AXR laser scanning confocal that will be housed within the BioFrontiers Institute’s Advanced Light Microscopy Core (ALMC) at the University of Colorado Boulder. The new microscope will replace our Nikon A1R laser scanning confocal that is approaching End-of-Life (April 2023) and is unable to meet the future needs of our Major and Minor Users. The Nikon AXR will allow our 14 Major and Minor Users that represent 21 different NIH-funded awards (16 R01, 2 R35, one each R03, R21 and RF1) to continue their research while pursuing new avenues of investigation in search of human health solutions utilizing live 3D cell-laden hydrogels and organoids as models. The Nikon AXR offers multiple advantages compared to currently available technologies. Our current Nikon A1R limits our Users with its a) small field of view (4096x4096 with the galvanometer, 512x512 with the resonant scanner) which slows image acquisition times, b) reduced piezo Z range (100 µm), and c) the lack of high- resolution objectives for long-term high-throughput live cell imaging due to immersion evaporation. Compared to the A1R, the Nikon AXR has a larger field of view for Nyquist sampling (up to 16x larger with the resonant scanner, depending on the objective), a faster resonant scanner for imaging rapid kinetics, the availability of larger piezo Z inserts allowing for fast, repeatable Z stacks (up to 600 µm), along with the Okolab environmental chamber, a water immersion dispenser that enables long-term live cell imaging and the screening of slides and multiwell plates using high-resolution water immersion objectives, and new detectors with improved sensitivity with two GaAsP and two multiAlkali detectors. Since it was purchased in 2012, the Nikon A1R enabled our NIH-funded Users to achieve scientific success resulting in 32 publications and nearly 1400 citations. However, it cannot be further upgraded to meet the future needs of the Major and Minor Users. Acquiring a Nikon AXR will enable our Users to advance their research projects beyond what is currently capable by growing to meet the future needs of their studies, including the ability to image entire multiwell plates over time using water immersion objectives, high-resolution repeatable Z stacks of large organoids (up to 600 µm in Z), and rapid, multidimensional imaging of diffusing objects. The Nikon A1R has been an essential resource for the BioFrontiers Institute and the University of Colorado Boulder. As the first instrument purchased for the ALMC, it has been used to great success, especially in terms of its applicability towards the multidimensional imaging of live samples to help unravel the fundamentals of biology to enhance human health. Such a tool is critical to our current and future success of biological investigation applied towards innovating human health solutions at our institution. Without the new Nikon AXR, numerous NIH investigators will be ...