ORGANOID SHARED RESOURCE ? ABSTRACT The Organoid Shared Resource was established to provide Cancer Center members with access to the reagents, equipment, and expertise needed to culture and perform experiments with three-dimensional organoid models. The organoid technology was introduced to the Cold Spring Harbor Laboratory Cancer Center in 2012 by David Tuveson, with the rationale that these three dimensional cultures recapitulate numerous aspects of primary tumor biology more faithfully than standard two-dimensional cell lines. There are now 18 Cancer Center member labs (47% of members) using human and murine organoids in their research, and organoids have been used in 40 Cancer Center publications or preprints. To support the growing use of organoids, the new Shared Resource was launched in 2020 with dedicated lab space and staff. The Organoid Shared Resource is being proposed in this application as a new Cancer Center Shared Resource, led by Faculty Head Camila dos Santos, Ph.D., and manager Dennis Plenker, Ph.D. The Shared Resource offers members centralized access to protocols for generating and working with organoid cultures, training in methods, and standardized culture reagents, as well as equipment for performing high-throughput chemical screens on either two dimensional cell lines or organoid cultures. Cancer Center members will benefit from access to a biorepository of human organoid models that have been validated and well characterized. The Shared Resource will be able to offer Cancer Center members substantial cost-savings due to bulk purchasing of culture reagents, and the development of protocols to produce media additives in-house. The use of organoids has already fostered several collaborative Cancer Center projects in line with Cancer Center strategic priorities, including investigating cancer health disparities in diverse populations, integrating quantitative and wet-bench biologists, and expanding translational research.