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Metabolites 2012, 2(1), 77-99; doi:10.3390/metabo2010077
Article

The Effect of LC-MS Data Preprocessing Methods on the Selection of Plasma Biomarkers in Fed vs. Fasted Rats

1,* , 1
, 2
 and 1
Received: 30 November 2011; in revised form: 6 January 2012 / Accepted: 6 January 2012 / Published: 18 January 2012
(This article belongs to the Special Issue Feature Papers)
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Abstract: The metabolic composition of plasma is affected by time passed since the last meal and by individual variation in metabolite clearance rates. Rat plasma in fed and fasted states was analyzed with liquid chromatography quadrupole-time-of-flight mass spectrometry (LC-QTOF) for an untargeted investigation of these metabolite patterns. The dataset was used to investigate the effect of data preprocessing on biomarker selection using three different softwares, MarkerLynxTM, MZmine, XCMS along with a customized preprocessing method that performs binning of m/z channels followed by summation through retention time. Direct comparison of selected features representing the fed or fasted state showed large differences between the softwares. Many false positive markers were obtained from custom data preprocessing compared with dedicated softwares while MarkerLynxTM provided better coverage of markers. However, marker selection was more reliable with the gap filling (or peak finding) algorithms present in MZmine and XCMS. Further identification of the putative markers revealed that many of the differences between the markers selected were due to variations in features representing adducts or daughter ions of the same metabolites or of compounds from the same chemical subclasses, e.g., lyso-phosphatidylcholines (LPCs) and lyso-phosphatidylethanolamines (LPEs). We conclude that despite considerable differences in the performance of the preprocessing tools we could extract the same biological information by any of them. Carnitine, branched-chain amino acids, LPCs and LPEs were identified by all methods as markers of the fed state whereas acetylcarnitine was abundant during fasting in rats.
Keywords: rat plasma; biomarkers; LC-QTOF; data pre-processing; MarkerLynx; MZmine; XCMS rat plasma; biomarkers; LC-QTOF; data pre-processing; MarkerLynx; MZmine; XCMS
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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MDPI and ACS Style

Gürdeniz, G.; Kristensen, M.; Skov, T.; Dragsted, L.O. The Effect of LC-MS Data Preprocessing Methods on the Selection of Plasma Biomarkers in Fed vs. Fasted Rats. Metabolites 2012, 2, 77-99.

AMA Style

Gürdeniz G, Kristensen M, Skov T, Dragsted LO. The Effect of LC-MS Data Preprocessing Methods on the Selection of Plasma Biomarkers in Fed vs. Fasted Rats. Metabolites. 2012; 2(1):77-99.

Chicago/Turabian Style

Gürdeniz, Gözde; Kristensen, Mette; Skov, Thomas; Dragsted, Lars O. 2012. "The Effect of LC-MS Data Preprocessing Methods on the Selection of Plasma Biomarkers in Fed vs. Fasted Rats." Metabolites 2, no. 1: 77-99.


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