1R24GM12135 COMMUNITY CRYSTALLIZATION RESOURCE FOR BIOLOGICAL MACROMOLECULES ADMINISTRATIVE SUPPLEMENT SUPPORT REQUEST PROJECT SUMMARY/ABSTRACT Macromolecular X-ray crystallography is one of the predominant methods used in structural biology, accounting for ~90% of solved structures in the Protein Data Bank, the primary repository and public database for making these three-dimensional structures of biomolecules available to researchers in all fields. To do crystallography, we need crystals. Finding conditions in which a macromolecule will crystallize remains a key challenge in this process, and we have focused on solving this problem at the High-Throughput Crystallization Screening Center. The Crystallization Center is a community resource that provides crystallization experiment set-up and imaging of a uniquely designed set of 1,536 crystallization conditions. Information about macromolecular crystallization is efficiently collected, so that structural investigations for the entire research community can rapidly progress. The Crystallization Center has a robust imaging schedule that facilitates immediate identification of positive crystallization outcomes. The unforeseen circumstances arising due to the extended COVID-19 pandemic have disrupted the operations of the Crystallization Center, as well as the research activities of the wide base of Crystallization Center users. This revision application seeks funds to address this unanticipated need to maintain operations in the Crystallization Center and to facilitate providing continuous uninterrupted services.