Orbitrap Illustration

Untargeted Metabolomics

Discovery-based relative quantitation allows a scientist to determine relative metabolite changes in one sample group relative to other sample groups without prior knowledge of the metabolites involved. Here we describe the most commonly used technique for relative quantitation of metabolites.

The metabolome is the entire collection of low molecular weight metabolites in a biological system, such as cells, tissues, fluids or whole organisms. Untargeted metabolomics refers to the global relative quantitative analysis of the metabolome.  The goals of untargeted metabolomics are to determine the metabolomic profiles of phenotypic diseases and healthy states, involving a complex set of genomic and proteomic changes. Presently, healthy and diseased states are followed using a limited number of specific assays that analyze only a few markers of distinct phenotypes. Untargeted metabolomics makes it possible to analyze hundreds to thousands of individual metabolites. Such detailed metabolic profiles can be the most direct reflection of the current state of a biological system and are the basis for the concept of personalized medicine. Other applications of untargeted metabolomics include agroscience and plant science;1 biomarkers;2,3 cardiovascular, diabetes and obesity disease research;4 drug discovery;5 environmental health;6 food safety;7 microbiology;8,9 nutrition;10 and systems biology.11,12

Discovery-based relative quantitation allows a scientist to determine relative metabolite changes in one sample group relative to other sample groups without prior knowledge of the metabolites involved. Here we describe the most commonly used technique for relative quantitation of metabolites.
 

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Untargeted Metabolomics Workflow Overview


Untargeted metabolomics studies involve comparing the relative abundances of metabolites in multiple samples without prior identification. Samples are run individually and common chromatographic features are used to align the various runs with software. Signals corresponding to individual metabolite ions are integrated over the LC time scale and compared between runs. This untargeted quantitation method is a powerful technique for identifying and quantifying relative changes in complex samples. For this technique, the mass spectrometer must have high sensitivity and be capable of measuring a wide dynamic range of analytes ranging from very hydrophilic to hydrophobic metabolites. Orbitrap-based mass spectrometers provide the high-resolution, accurate-mass measurements required for LC-MS relative quantitation experiments.






 




resources

Metabolomic Profiling in Drug Discovery: Understanding the Factors that Influence a Metabolomics Study and Strategies to Reduce Biochemical and Chemical Noise

Sanders M, Hnatyshyn S, Robertson D, Reily M, McClure T, Athanas M, Wang J, Yang P, Huang H, Peake D.
Application Note 562

 
Metabolite Profiling and Identification Employing High Resolution MS Strategies and Dedicated Software

Welchman H, Portwood D, Seymour M, Baxter C, Earll M, Ament Z, Peake D, Seymour G, Hodgman C, Hornshaw M, Oppermann M.
Application Note 550