Metabolic Flux
Quantifying metabolic pathway activity with 13C isotope tracers
Isotope tracers are essential tools for monitoring metabolic pathway activity, i.e. flux. To quantitate flux in central carbon metabolism in cultured mammalian cells, D-glucose (13C6, 99%) (CLM-1396) or L-glutamine (13C5, 99%) (CLM-1822) is added to media lacking these principal nutrients. Cells are grown in the labeled media, and metabolite labeling is measured by GC-MS or LC-MS.
L-Glutamine (13C5) — CLM-1822
Glucose has traditionally been considered to be the primary carbon source for many cell types, especially cancer cells. Recent studies show, however, that glutamine often plays a predominant role in feeding the tricarboxylic acid (TCA) cycle. The extent of contribution of glutamine to TCA cycle four-carbon units can be measured based on malate and aspartate labeling, and to two-carbon units based on acetyl-CoA and fatty acid labeling.
🔬 Citrate: a particularly informative molecule
Citrate is a particularly informative molecule, because it reflects both two- and four-carbon units of the TCA cycle. With modern instrumentation, it is possible to measure in parallel the isotope labeling of all of these species, and dozens more, enabling systems-level flux quantitation.
These methods can also translate to the in vivo setting, with mice or patients infused with labeled nutrients prior to resection of a tumor or other tissue specimen. The importance of metabolism in both bioengineering and disease pathophysiology is leading to wide application of these methods across the biochemical sciences.
Frequently Asked Questions
What is 13C-MFA?
13C-MFA, or 13C metabolic flux analysis, is a stable isotope-assisted technique that is the gold standard for accurate and precise flux determination. Flux can be inferred utilizing stable isotope-labeled tracers in combination with mass spectrometry (MS) or nuclear magnetic resonance (NMR).
Does Eurisotop offer different grades of products for metabolic flux analysis?
Yes, Eurisotop provides additional testing on many of our products as a service to our customers.
