Tandem mass spectrometry for measuring stable-isotope labeling

Measuring metabolic rates by 13C-metabolic flux analysis (13C-MFA) is of central importance for metabolic engineers and biomedical investigators. Enhanced knowledge of in vivo fluxes can be applied to reengineer the metabolic, regulatory, and phenotypic characteristics of organisms and help uncover the mechanisms of human ailments such as cancer and diabetes. To determine accurate and precise fluxes by 13C-MFA advanced methods for measuring stable-isotope labeling are needed. The application of tandem mass spectrometry is emerging as a new promising technique that has significant advantages over traditional MS and NMR based methods. With further refinement, tandem MS has the potential to become the new gold standard for measuring isotopic labeling for 13C-flux studies.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (187 K)Download as PowerPoint slideHighlights► Tandem MS combines efficient separation, high sensitivity and selectivity. ► Tandem MS is used for measuring stable-isotopic labeling for 13C-flux analysis. ► Complete positional isotopomer distribution of aspartate was measured by tandem MS. ► Measurement accuracy is improved by 2-fold to10-fold compared to GC–MS and LC–MS. ► Validated libraries of parent–daughter fragments are needed for accurate 13C-analysis.