Metabolite concentrations, fluxes, and free energies constitute the basis for understanding and controlling metabolism. Mass spectrometry and stable isotopes are integral tools in quantifying these metabolic features. For absolute metabolite concentration and flux measurement, 13C internal standards and tracers have been the gold standard. In contrast, no established methods exist for comprehensive thermodynamic quantitation under physiological environments. Recently, using high-resolution mass spectrometry and multi-isotope tracing, flux quantitation has been increasingly adopted in broader metabolism. The improved flux quantitation led to determination of Gibbs free energy of reaction (ΔG) in central carbon metabolism using a relationship between reaction reversibility and thermodynamic driving force. Here we highlight recent advances in multi-isotope tracing for metabolic flux and free energy analysis.

中文翻译：

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使用多种同位素的代谢通量分析和通量组学驱动的反应自由能测定。

代谢物的浓度，通量和自由能是理解和控制代谢的基础。质谱和稳定同位素是量化这些代谢特征的不可或缺的工具。对于绝对代谢物浓度和通量测量，13 C内标和示踪剂已成为金标准。相反，在生理环境下不存在用于综合热力学定量的既定方法。最近，使用高分辨率质谱和多同位素示踪，通量定量已越来越广泛地用于更广泛的代谢中。改进的通量定量分析通过反应可逆性和热力学驱动力之间的关系，确定了中心碳代谢中的吉布斯反应自由能（ΔG）。