A roadmap for interpreting 13C metabolite labeling patterns from cells

Measuring intracellular metabolism has increasingly led to important insights in biomedical research. C-13 tracer analysis, although less information-rich than quantitative C-13 flux analysis that requires computational data integration, has been established as a time-efficient method to unravel relative pathway activities, qualitative changes in pathway contributions, and nutrient contributions. Here, we review selected key issues in interpreting C-13 metabolite labeling patterns, with the goal of drawing accurate conclusions from steady state and dynamic stable isotopic tracer experiments.