The untargeted metabolomics platforms based on mass spectrometry are qualitative discovery platforms. The Mayo Clinic Metabolomics Core provides basic statistics and informatics to investigators as part of its untargeted analysis service.
The core provides investigators with a list of accurate mass molecular weights of metabolite components that are different between groups. Core staff members use the METLIN database to provide putative metabolite identification. Further group comparisons are made using unsupervised principal component analysis, analysis of variance (ANOVA), 3D plot and heat map, and a partial least square discrimination analysis (PLS-DA).
The Mayo Clinic Metabolomics Core analyzes GCMS data using the Automated Mass Spectral Deconvolution and Identification System (AMDIS) for peak deconvolution and identification against Fiehn Library. The core staff then submits the AMDIS files to SpectConnect — an online open source tool — for identification of conserved metabolites and biomarker discovery.
The Mayo Clinic Metabolomics Core acquires lipid extracts via full scans and data-dependent scans according to the ThermoFisher Lipidomics platform. The core staff identifies lipids on LipidSearch software, and then exports them for statistical analysis.
Central carbon platform
The core has monitored central carbon metabolites (219 compounds) according to the Agilent Metabolomics dynamic multiple reaction monitoring (dMRM) method. The staff searches and confirms analytes against an Agilent-curated dMRM database with retention time. Relative abundances between sample sets are derived via multivariate analysis on Agilent Mass Professional Profile software (MPP).
Nuclear magnetic resonance (NMR) platform
The Metabolomics Core collects data via multinuclear (1H; 13C; 31P) 1D and 2D NMR. Services include data processing, metabolite identification and quantitation, and multivariate analysis and interpretation of metabolomic changes using Chenomx and SIMCA software.
Additional informatics services are available as needed. For example, the core can export differentially expressed metabolites with annotations and compound identifiers into web-based tools for pathways enrichment and network analysis using MetaCore and Ingenuity software.