Inaccurate quantitation of palmitate in metabolomics and isotope tracer studies due to plastics
Inaccurate quantitation of palmitate in metabolomics and isotope tracer studies due to plastics
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DOI：
10.1007/s11306-016-1081-y
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发表时间：
2016-09-01
期刊：
影响因子：
3.6
通讯作者：
Patti, Gary J.
中科院分区：
文献类型：
--
作者：
Yao, Cong-Hui;Liu, Gao-Yuan;Patti, Gary J.
简介 棕榈酸是脂肪酸合酶释放的典型最终产物，引起了许多代谢组学研究人员的兴趣。尽管使用质谱法可以轻松检测棕榈酸酯，但许多代谢组学平台涉及使用引入棕榈酸酯竞争背景信号的塑料耗材。 目的 本研究的目的是量化代谢组学和同位素示踪剂研究中的棕榈酸酯污染，并检查减少误差方法的可靠性。 方法 我们测量了 4 个塑料耗材供应商与几种不同提取溶剂结合使用时棕榈酸酯污染带来的定量误差。 结果 背景棕榈酸信号比 400 万个 3T3-L1 细胞的生物棕榈酸信号高六倍。重要的是，棕榈酸酯污染信号在塑料耗材之间存在很大差异（即使在同一批次内），因此无法通过减去从空白中测量的背景来准确去除。除了影响相对和绝对定量外，一次性塑料中的棕榈酸酯背景信号还导致同位素示踪实验中标记的棕榈酸酯的低估。结论在测量棕榈酸酯标准溶液时，使用玻璃瓶和玻璃移液器可获得最佳结果。然而，在引入样品之前，可以通过用甲醇预冲洗塑料瓶和塑料移液器吸头来消除大部分棕榈酸酯背景信号。对于同位素示踪剂研究，还可以通过估计棕榈酰肉碱中的棕榈酸盐富集度来最大程度地减少误差，因为棕榈酰肉碱没有来自塑料消耗品的竞争性污染信号。
Introduction Palmitate, the typical end product released from fatty acid synthase, is of interest to many researchers performing metabolomics. Although palmitate can be readily detected by using mass spectrometry, many metabolomic platforms involve the use of plastic consumables that introduce a competing background signal of palmitate.Objectives The goal of this study was to quantify palmitate contamination in metabolomics and isotope tracer studies and to examine the reliability of approaches for reducing error.Methods We measured the quantitative error introduced by palmitate contamination from 4 vendors of plastic consumables used in combination with several different extraction solvents.Results The background palmitate signal was as much as sixfold higher than the biological palmitate signal from 4 million 3T3-L1 cells. Importantly, the palmitate contamination signal was highly variable between plastic consumables (even within the same lot) and therefore could not be accurately removed by subtracting the background as measured from a blank. In addition to affecting relative and absolute quantitation, the palmitate background signal from disposable plastics also led to the underestimation of labeled palmitate in isotope tracer experiments.Conclusion When measuring palmitate standard solutions, the best results were obtained when glass vials and glass pipettes were used. However, much of the palmitate background signal could be eliminated by pre-rinsing plastic vials and plastic pipette tips with methanol prior to sample introduction. For isotope tracer studies, error could also be minimized by estimating palmitate enrichment from palmitoylcarnitine, which does not have a competing contamination signal from plastic consumables.