University of North Texas 
13C-Stable Isotope Labeling
Stable isotope labeling (13C, 15N, 18O...) is a technique that can lead to a better understanding of the cellular metabolism (Chokkathukalam et al., 2014). Indeed, combined with state-of-the art mass spectrometers, this approach is very powerful in unraveling novel markers, pathways, and determining the consumption/production rates of metabolites (Fluxomics) in a living organism.
13C-Amino Acids
13C-labeled amino acids are analyzed using an Agilent 1290 Infinity II coupled to an ABSciex QTRAP 6500+ LC-MS/MS system. The analytical method is detailed in a peer-review paper written by Cocuron et al. (2017). The run time is 10 minutes.
13C-Organic acids and 13C-Phosphorylated Compounds
13C-Phosphorylated compounds and 13C-organic acids labeling is assessed using an Agilent 1290 Infinity II coupled to an ABSciex QTRAP 6500+ LC-MS/MS system. The analytical method is described in two peer-review papers published by Koubaa et al. (2013), and Cocuron and Alonso (2014). Note that organic acids can be separated in 60 minutes whereas phosphorylated compounds in 80 minutes.
13C-Sugars & 13C-Sugar Alcohols
13C-Sugars and 13C-sugar alcohols are analyzed using an Agilent 1290 Infinity II coupled to an ABSciex QTRAP 6500+ LC-MS/MS system. The analytical method to measure the 13C-labeling of sugars and sugar alcohols is similar to the one published by Cocuron et al. (2014), except scheduled MRMs are setup to follow the isotopomers corresponding to each sugar and sugar alcohol. The run time is 20 minutes.
13C-Fatty Acids
13C-labeled fatty acids are extracted, then derivatized into Fatty Acid Butylamides (FABAs) using n-butylamine as previously described by Allen et al. 2007. The separation and the detection of 13C-FABAs are done, respectively, by a TG5-MS (30 m x 0.25 mm x 0.50 micron) column from ThermoFisher and the Thermo Trace 1310 Gas Chromatography Coupled to an ISQ Single Quadrupole Mass Spectrometer. The run time is 45 minutes.