Metabolic Research

CIL offers the most complete listing of stable isotopically labeled metabolic substrates available. These metabolic substrates are labeled with 13C, 15N, 18O, D, as well as other stable isotopes. Some of the many applications for these materials include the utilization of amino acids for protein turnover studies, carbohydrates for glucose metabolism studies, and fatty acids for lipolysis research. Stable isotope labeling of these materials allows investigators to study metabolic pathways in living systems in a manner which is safe, accurate and noninvasive.

Isotope dilution mass spectrometry (IDMS) is inarguably the most accurate, sensitive, reproducible and popular method available for quantifying small- and intermediate-sized molecules in a wide range of sample types. One primary reason why compounds enriched in stable isotopes make ideal internal standards for comparative or absolute quantitation using mass spectrometry is that separate signals from the “heavy” (isotope enriched) and “light” (native) forms of the same compound are detected simultaneously.

13C and 15N nuclei are NMR active, and thus compounds enriched in these isotopes allow for magnetic resonance detection. The large chemical shift range and favorable relaxation properties of the 13C nucleus has made 13C-enriched substrates highly valuable probes of cellular chemistry and metabolism, particularly in the rapidly advancing field of hyperpolarization.

CIL recognizes the importance of high chemical purity and isotopic enrichment for metabolic studies. For this reason, all products are tested to the meet high specifications for both. All products are shipped with a Certificate of Analysis that indicates the passing results and an MSDS to describe the product even further. CIL may be able to provide additional data upon request. CIL offers different grades of products for your metabolic research, which include research grade, microbiological and pyrogen tested, and cGMP grade. An Enhanced Technical Data Package is also available for some products; please inquire for details.


Researchers employ stable isotope techniques to study a wide variety of metabolic disorders and diseases including Alzheimer’s, Parkinson’s, cancer, diabetes, and obesity.


It not surprising that many developments in the field of magnetic resonance are aimed to improve sensitivity. One can blame NMR spectroscopy’s inherently poor sensitivity on the very small population differences between magnetically induced nuclear spin states.


CIL offers a wide array of compounds labeled with 13C, 15N, and 17O for magnetic resonance spectroscopy (MRS) research and magnetic resonance imaging (MRI).

Metabolic Flux

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.

Deuterated Metabolic Imaging (DMI)

The first experiments with DMI were done in the 1980s but were overshadowed by other nuclei until 2018. DMI has garnered much interest since then because of its ability to study metabolism in three dimensions in a noninvasive manner using magnetic resonance spectroscopy (MRS).