Project Abstract Funds are being requested for the purchase of an X-Band Continuous-Wave Electron Paramagnetic Resonance Spectrometer, which will enhance the interdisciplinary and multicampus biomedical research capability of the University of Puerto Rico (UPR) College of Natural Sciences in Chemistry and also the UPR Medical Sciences Campus Department of Pharmacology and Toxicology and Department of Physiology and Biophysics. Following the devastating events of natural disasters and major economic budget cuts, researchers are aiming to expand the resources available to rebuild and refocus their research efforts to multiply their productivity and maintain excellence of graduate student development. A state-of-the-art EPR with the sensitivity to directly probe paramagnetic species in biological materials and living organisms would dramatically expand our ability to answer important questions that pertain to insight into the development and progression of diseases, drug design and delivery, and studying structural changes that impact on biomolecular function and interactions. No other technique can directly study such species with such a high degree of specificity. The absence of a paramagnetic species does not limit the utility of an EPR to study the activity of biomedically relevant ions, molecules, and materials as paramagnetic spin labels can be covalently linked to these agents. The instrumentation will be located in the Proteomics and Nuclear Magnetic Resonance instrumentation space at the Molecular Science Research Center of the UPR Río Piedras (RP) campus and will be utilized by a diverse team of researchers from UPR Rio Piedras, Mayagüez, and Centro Medico campuses composed of Drs. Tinoco, Rodríguez-Berrios, Bayro, Palai, Weiner, Griebenow, Montes, Colón, López-Garriga, Meléndez, Ayala-Peña, and Javadov. This team consists of early career and senior level researchers. This instrumentation will be made available to other investigators in the College of Natural Sciences of all institutions of the UPR system including its Medical Sciences campus. It will also be implemented in the creation of new laboratory experiences for students of the UPR RP Protein Biochemistry course (Chem 4865). The instrument will be presented in exhibition workshops for faculty and student participants of the NIH RISE, MARC, and INBRE and other STEM traineeship programs to attract additional biomedical investigators as users and to foster interdisciplinary collaborations between these investigators.