Project Summary/Abstract The purpose of this proposal is to acquire funds to purchase a new Thermo Scientific Orbitrap Eclipse Tribrid ETD-enabled mass spectrometer and fully dedicated Dionex Ultimate 3000 RSLCnano ultra-high performance liquid chromatography system to enable new, cutting-edge proteomics analysis at the University of Connecticut (UConn). The proposed instrumentation will be an integral part of the UConn Proteomics and Metabolomics Facility (PMF) located on the Storrs academic campus. PMF is a mass spectrometry (MS)-based shared resource that provides the entire UConn research community with innovative and customized methods for the identification and quantification of peptides, proteins, and small molecule metabolites in order to elucidate the molecular mechanisms that underlie human disease. Since opening 2.5 years ago, PMF has already provided sophisticated analytical services to more than 80 laboratories and many of these have multiple projects ongoing simultaneously. Currently, all proteomics experiments at UConn are analyzed in PMF using a single, refurbished Thermo Scientific Q Exactive HF mass spectrometer purchased in 2015; this is the only high resolution advanced proteomics-capable mass spectrometer available to UConn investigators. As a result, it consistently runs at full capacity and lacks crucial analytical options required for NIH-funded research. The requested instrumentation will exclusively provide the substantial technological upgrades required for health- related projects focused on elucidating the protein contributions to various human diseases. These vital upgrades include maximum sensitivity for low abundance ion detection, superior depth of proteome coverage for every experiment, new peptide/protein dissociation techniques unavailable at UConn, and novel methods to provide the utmost accuracy of quantification for label-based, multiplexed proteomics via Real-Time Search Synchronous Precursor Selection. These features are uniquely exhibited on the proposed instrumentation and are required for 15 (13 NIH-funded) investigators at the UConn Storrs and UConn Health medical research campuses. Conversely, our single existing instrument suffers from poorer sensitivity, limited depth of coverage particularly for protein-limited samples, tandem MS by only one peptide dissociation technique, and inaccurate quantification for label-based, multiplexed analyses. Therefore, acquisition of the Orbitrap Eclipse is necessary to transform scientific research for NIH-funded projects that we cannot currently complete successfully. By implementing new technologies featured on the Orbitrap Eclipse, PMF will permit breakthrough research that requires analysis of severely limited protein samples, full characterization of important regulatory post- translational modifications, and identification of new protein targets implicated in disease using extremely accurate quantitative proteomics. Overall, these advancements will allow NIH-...