PROJECT SUMMARY/ABSTRACT Cutting-edge research at the University of Wisconsin-Madison has led to pioneering efforts in quantitative and investigational proteomics, functional glycomic interrogation, structural characterization of bioactive molecules, natural product discovery and metabolomic profiling with significant focus on human health and disease. Upon evaluating the current needs of 26 NIH-supported investigators and dutiful comparison of commercial high- resolution mass spectrometer offerings, this proposal seeks funding for the purchase of instrumentation capable of alleviating the limitations in analytical sensitivity, mass resolution, ion separation, and duty cycle presented by currently-accessible spectrometers and that directly benefits each research focus. Given the complexity of human and disease-relevant samples, electrospray (ESI) and matrix-assisted laser desorption ionization (MALDI)-based mass spectrometry (MS) instrumentation demonstrate limitations in sensitivity due to limited precursor selection, interference from singly-charged ions, and low duty cycles that eliminate up to 90% of ions prior to analysis. Of the species that do survive initial selection, identification of biomolecules through tandem MS scans can be severely hindered by precursor co-isolation and signal suppression of low abundance analytes. With these limitations in mind, emerging literature and personal evaluations demonstrate that trapped ion mobility spectrometry (TIMS) is the paradigm uniquely capable of expanding analytical sensitivity in proteomic, glycoproteomic, and small molecule analyses, while also presenting the highest gas-phase resolution regime for structural and conformational investigation. The innovative instrument design of the Bruker timsTOF fleX MS system incorporates several novel design improvements to the source area, TIMS cell, and quadrupole to dramatically enhance instrument performance. Our initial testing of the timsTOF fleX and comparison to other current high-resolution orbitrap and ion mobility instruments indicate the acquisition of the timsTOF fleX provides the greatest benefit to our research partners, as it is the most effective regime in proteomic, glycoproteomic, metabolomic and ion mobility analysis. This new instrument will provide advanced MS capabilities to support the research of 26 highly productive NIH-funded investigators with 73 ongoing projects. Progress on this broad array of projects will be catalyzed by the effective usage of the new instrument through close cooperation among the user groups, Dr. Li, a highly productive faculty member with more than 27 years of experience in biological mass spectrometry, and Dr. Scarlett, the UW-Madison Pharmacy-MS Facility Director. Alternative instruments or allocation of funds would certainly be considered, should this application be funded.