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Metabolomics

, Volume 11, Issue 4, pp 851–860 | Cite as

Experiment design beyond gut feeling: statistical tests and power to detect differential metabolites in mass spectrometry data

  • Diana TrutschelEmail author
  • Stephan Schmidt
  • Ivo Grosse
  • Steffen Neumann
Original Article

Abstract

Univariate hypotheses tests such as Student’s t test or variance analysis (ANOVA) can help to answer a variety of questions in metabolomics data analysis. The statistical power of these tests depends on the setup of the experiment, the experimental design and the analytical variance of the actual observations. In this paper, we demonstrate how a well-designed pilot study prior to an experiment with the aim to find differences between e.g. several genotypes, can help to determine the variance at multiple levels ranging from biological variance, sample preparation to instrumental variances. Next, we illustrate how these variances can be used to obtain several parameters (e.g. minimum statistically significant effect, number of required replicates and error probabilities) which influence the design of the actual study. In particular, we are going to sketch how technical replicates can improve the performance of a test, when they are correctly used in the statistical analysis, e.g. with a hierarchical model. Finally, we demonstrate the process of evaluating the trade-off between different experimental designs with different replication strategies. The choice of an experimental design beyond the gut feeling can be influenced by factors such as costs, sample availability and the accuracy of of the tests. We use metabolite profiles of the model plant Arabidopsis thaliana measured on an UPLC-ESI/QqTOF-MS as real-world dataset, but the approach is equally applicable to other sample types and measurement methods like NMR based metabolomics.

Keywords

Metabolomics Statistics Variances Hierarchical experiment design 

Notes

Conflict of interest

The authors declare that they have no conflict of interest.

Compliance with ethical requirements

This article does not contain any studies with human or animal subjects.

Supplementary material

11306_2014_742_MOESM1_ESM.pdf (317 kb)
Supplementary material 1 (PDF 318 KB)
11306_2014_742_MOESM2_ESM.r (12 kb)
Supplementary material 1 (R 13 KB)
11306_2014_742_MOESM3_ESM.pdf (250 kb)
Supplementary material 1 (PDF 251 KB)
11306_2014_742_MOESM4_ESM.rnw (17 kb)
Supplementary material 1 (RNW 18 KB)

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Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  • Diana Trutschel
    • 1
    Email author
  • Stephan Schmidt
    • 1
  • Ivo Grosse
    • 2
    • 3
  • Steffen Neumann
    • 1
  1. 1.Department of Stress and Developmental BiologyLeibniz Institute of Plant BiochemistryHalleGermany
  2. 2.Institute of Computer ScienceMartin-Luther-University Halle-WittenbergHalleGermany
  3. 3.German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-LeipzigLeipzigGermany

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