top of page
Metabolomics / Biomarker discovery
Quantitative / Targeted metabolomics panels
We measure several hundreds of metabolites using absolute quantification, utilizing stable isotope dilution, 6-8 pt standard curves and 4 levels of QC analysis within each batch. Most quantitative assays are run on a triple quadrupole LC-MS/MS system (API-4500, AB Sciex). Panels include:
Intracellular energy metabolite panel: Primary metabolites and cofactors associated with energy production in the cell. Absolute quantification of nucleotides (e.g. ATP, ADP, AMP, GTP, GDP,...etc), sugar phosphates (glycolysis, pentose phosphate intermediates), coenzymes/cofactors (e.g. NADH, NAD+, acetyl-CoA, etc). This platform uses either cell culture or tissue as the matrix for analysis (Compound list).
Lipidomics Panel: Phospholipids, fatty acids (saturated, mono- and poly- unsaturated), eicosanoids, acylcarnitines, and bile acids. Relative quantification of a variety of hydrophobic metabolite classes critical for metabolism, modulating inflammation, and signaling. Peaks are normalized to appropriate stable isotope internal standards for ideal inter-sample comparisons. Method was developed for plasma and serum samples, but is adaptable to all types of biological tissues that contain measurable levels of these metabolites (Compound list). Lipid compound list can be customized for individual projects.
Global metabolite panel: (ideal for plasma, serum, urine, or even cells). These several hundred metabolites are found both intra- and extracellularly and include amino acids, organic acids, acylcarnitines, purines and pyrimidines, bile acids and more, providing a diverse metabolic profile. The full method uses two separate runs to cover multiple ionization modes and is measured in conjuction with the UCSD Biochemical Genetics Lab (www.ucsdbglab.org)(Compound list). We have also developed an abridged single run version of this panel, run at Clarus Analytical (Compound list).
Nearly 40 compounds are quantified in this single run, with a stable isotope included for each compound
Resolution of each phosphorylation state
ensures no interferences in metabolite quantitation
Biomarker / Untargeted platform
We can perform untargeted biomarker research using a high resolution Q-TOF (AB-Sciex 5600 Triple TOF MS) to monitor and compare thousands of analytes from biological samples. Compounds of interest from statistical analysis are identified using either database matching of MS/MS patterns, comparison to standards, or de-novo identification using ultra-high resolution analysis (Orbitrap Fusion, Thermo-Fisher Scientific)
Univariate and multivariate statistical analysis, as well as pathway enrichment analysis can be performed. Multivariate analysis can include either unsupervised (PCA) or supervised (PLS-DA) analysis, with the goal of creating a model that characterizes a particular cohort by a metabolic signature. Pathway enrichment analysis is done to identify particular pathways of interest from a dataset. Univariate analysis (e.g. T-test or ANOVA analysis) will be done to identify key fold changes with statistical significance.
Collaboration with proteomics core at University of California-San Diego
If you are interested in quantitative proteomics analysis of the same sample from which metabolite profiling is performed, we have optimized a single extraction procedure to analyze both from the same sample. This work is done in collaboration with the Biomolecular proteomic facility at UCSD, directed by Majid Ghassemian. PhD. We will perform the initial extraction, run the metabolomics experiments, and coordinate the proteomic analysis with Dr. Ghassemian, who will analyze the protein pellet of the extraction. We will provide a single full report at the conclusion of both experiments. Specific types of proteomic services can be found at: http://bpmsf.ucsd.edu/protein-based-analysis/protein-quantification/index.html
bottom of page