Elucidation of cellular metabolism via metabolomics and stable-isotope assisted metabolomics.

Metabolomics and metabolic flux analysis (MFA) are powerful tools in the arsenal of methodologies of systems biology. Currently, metabolomics techniques are applied routinely for biomarker determination. However, standard metabolomics techniques only provide static information about absolute or relative metabolite amounts. The application of stable-isotope tracers has opened up a new dimension to metabolomics by providing dynamic information of intracellular fluxes and, by extension, enzyme activities. In the first part of the manuscript we review experimental and computational technologies applicable for metabolomics analyses. In the second part we present current technologies based on the use of stable isotopes and their applications to the analysis of cellular metabolism. Beginning with the determination of mass isotopomer distributions (MIDs), we review technologies for metabolic flux analysis (MFA) and conclude with the presentation of a new methodology for the non-targeted analysis of stable-isotope labeled metabolomics data.