The goal of the Center for Cellular Metabolism Research in Oklahoma (CMRO) Phase I COBRE proposal is to cultivate novel multidisciplinary research focusing on metabolism. As part of this overall goal, we created the Metabolic Phenotyping Core to facilitate the transition of our COBRE investigators to independent R01 funding and to develop metabolic research in Oklahoma. The projects proposed by the COBRE investigators seek to understand the mechanisms by which cellular metabolic processes drive or result from cardiovascular disease, autoimmune disease, and cancer. Because cellular metabolism is complex and poses many biological and technical challenges, the Core will provide a team of highly-trained directors and PhD-level scientific staff, access to state-of-the-art instruments that are carefully maintained, and mentored training in experimental design, implementation, and interpretation of metabolic data. The Core addresses three critical needs to support our COBRE investigators: 1) assessment of cellular respiration and mitochondrial function, 2) isotopic metabolic tracer analyses, and 3) metabolite-based metabolic profiling and bioinformatic analyses. To meet these needs, our specific aims are to: 1) provide expertise with study design, assay optimization, data analysis, and interpretation of results, as well as evaluate and develop new methodologies for in vivo metabolic phenotyping, and 2) provide COBRE investigators access to centralized equipment and appropriate scientific and technical training to facilitate the development of new expertise in cellular metabolic assessment. To support the COBRE Investigators, the Core will provide instrumentation for cellular respiration and mitochondrial function (e.g. Seahorse, Oroboros, and EPR), metabolite tracer analysis (LC-MS/MS), and metabolic profiling (GC-MS and GC-MS/MS). The Core will be directed by Dr. Timothy Griffin and Co-directed by Dr. Benjamin Miller. Both directors have over 20 years of experience in studies of metabolism and previous experience in leadership positions. The Core has a proposed structure that facilitates clearly-defined roles of support staff as well as transparent decision-making processes. Through this structure, the Core will foster a mentoring and collaborative culture, promote an idea- and method-sharing environment, and contribute to the establishment of a sustainable resource for metabolic research for COBRE Investigators as well as other researchers in Oklahoma.