Summary: The Lundquist Institute (TLI) is requesting funds to purchase a Leica STELLARIS confocal microscope to be housed in its established, centrally managed core facility. This new system is intended to replace an aging 12- year-old Leica SP8 microscope that no longer meets the evolving needs of our research community. A diverse user group of 12 investigators (10 of whom are NIH-funded), who are all making significant and pioneering contributions to cross- disciplinary research at the interface between developmental biology, cell biology, molecular biology, cancer, endocrinology, neurobiology, immunology, and host-pathogen interactions, will immediately benefit from the transformative imaging capabilities of the instrument. The STELLARIS system offers major advancements in confocal imaging technology, including a tunable white light pulsed laser for fluorescence lifetime imaging microscopy (FLIM), integrated with the high-speed FALCON FLIM platform and capable of multiplexing up to 11 spectral channels. These features provide users with quantitative imaging modalities to monitor complex dynamic processes in live and fixed samples. The instrument also includes LIGHTNING super-resolution capabilities based on adaptive deconvolution, expanded spatial coverage, and Leica's proprietary HyD detectors with tunable spectral sensitivity (1-nm precision, 400–850 nm), enabling high- resolution, low-phototoxicity imaging across a wide range of fluorophores. Acquisition of this system will ensure continued access to state-of-the-art imaging technology, enabling investigators to generate high-quality, multidimensional datasets and address increasingly complex biological questions. This instrument will directly enhance the rigor, reproducibility, and competitiveness of NIH-supported research at TLI by facilitating transformative insights into molecular and cellular mechanisms of health and disease.