Targeted Metabolomic Methods for 13C Stable Isotope Labeling with Uniformly Labeled Glucose and Glutamine Using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS).

Heavy carbon labeling has emerged as a popular way to study metabolic diseases. However, most carbon labeling techniques use untargeted mass spectrometry, which typically requires dependence on a research core and specialized software. By combining published 13C labeling patterns and known enzyme reactions, an optimized targeted mass spectrometry method was generated to measure stable isotope labeling with carbon-13 through glycolysis, the tricarboxylic acid cycle, the hexosamine biosynthetic pathway, and glutaminolysis using uniformly labeled glucose or glutamine. This method provides a novel and adaptable approach to investigate pointed hypotheses on the utilization of glucose or glutamine in disease states and models.