OBJECTIVE: In this tutorial we aim to (1) define similarities and differences between different analytical approaches applied in metabolomics and (2) define how amounts or absolute concentrations of endogenous metabolites can be determined together with the advantages and limitations of each approach in relation to the accuracy and precision when concentrations are reported.
UNASSIGNED: The pre-analysis knowledge of metabolites to be targeted, the requirement for (normalised) peak responses or absolute concentrations to be reported and the number of metabolites to be reported define whether an untargeted, targeted or semi-targeted method is applied. Fully untargeted methods can only provide (normalised) peak responses and fold changes which can be reported even when the structural identity of the metabolite is not known. Targeted methods, where the analytes are known prior to the analysis, can also report fold changes. Semi-targeted methods apply a mix of characteristics of both untargeted and targeted assays. For the reporting of absolute concentrations of metabolites, the analytes are not only predefined but optimized analytical methods should be developed and validated for each analyte so that the accuracy and precision of concentration data collected for biological samples can be reported as fit for purpose and be reviewed by the scientific community.
目的:在本教程中,我们旨在(1)定义代谢组学中应用的不同分析方法之间的相似性和差异,以及(2)定义如何确定内源性代谢物的量或绝对浓度以及每种方法在报告浓度时的准确性和准确性方面的优势和局限性。
■要针对的代谢物的预分析知识,(标准化)峰响应或绝对浓度的要求被报告和代谢物的数量被报告定义是否非目标,采用靶向或半靶向方法。完全非靶向的方法只能提供(标准化的)峰响应和倍数变化,即使在代谢物的结构特性未知时也可以报告。有针对性的方法,其中分析物在分析之前是已知的,也可以报告折叠变化。半靶向方法应用非靶向和靶向测定两者的特征的混合。对于代谢物的绝对浓度的报告,分析物不仅是预定义的,而且应该为每种分析物开发和验证优化的分析方法,以便为生物样品收集的浓度数据的准确性和精确度可以报告为符合目的,并由科学界审查。