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Updated: May 31, 2026

Stable Isotopic Profiling of Intermediary Metabolic Flux in Developing and Adult Stage Caenorhabditis elegans
Published on: February 27, 2011
Evaluation of isotope discrimination in (13)C-based metabolic flux analysis
1Department of Energy, Environmental and Chemical Engineering, Washington University, St. Louis, MO 63130, USA.
Abstract:
In a (13)C experiment for metabolic flux analysis ((13)C MFA), we examined isotope discrimination by measuring the labeling of glucose, amino acids, and hexose monophosphates via mass spectrometry. When Escherichia coli grew in a mix of 20% fully labeled and 80% naturally labeled glucose medium, the cell metabolism favored light isotopes and the measured isotopic ratios (δ(13)C) were in the range of -35 to -92. Glucose transporters might play an important role in such isotopic fractionation. Flux analysis showed that both isotopic discrimination and isotopic impurities in labeled substrates could affect the solution of (13)C MFA.

