High-throughput 'omics analysis platforms are the technologies of choice for analyzing complex mixtures derived from tissues and biological matrices such as liver, feces, intestine, blood and urine. To maximize our capability for deciphering the mechanism and therapy for liver injury, nutrition and gut:liver interactions, and liver:environment/toxin/drug interactions, we propose an OMICS Core in this Hepatobiology and Toxicology COBRE proposal. Our OMICS Core is composed of three major components including Metabolomics Core, Proteomics Core, and Bioinformatics. The overarching goal of the OMICS Core is to support the proposed COBRE research. This goal will be met through application of state of the art separations science and mass spectrometry techniques to analyze research samples containing complex mixtures of metabolites, proteins and protein fragments. This goal is achieved through the following aims: Specific Aim 1: Application of liquid chromatography mass spectrometry (LC-MS), comprehensive two- dimensional gas chromatography time-of-flight mass spectrometry (GCxGC/TOF-MS) and integrated laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) platforms for quantitative analysis of metabolites, metal ions, and metal-protein complex in biological samples. Specific Aim 2: Application of high-resolution multidimensional liquid chromatography mass spectrometry (MDLC-MS) and affinity enrichment methods for targeted protein quantification.