Metabolic footprinting relies not on measurement of the intracellular metabolites, but on monitoring of the metabolites consumed from, and secreted into, the culture medium by yeast batch or human tissues by using direct-injection MS.

• 代谢足迹技术是利用直接注射质谱方法，在分析系统中以培养基为介质，监控细胞从生长培养基中消耗营养物以及分泌代谢物至培养基的全部过程。