Please note that this version of the script has been tested using Bioconductor version 3.8 and R version 3.5.3.
MStractor is an R workflow for non-targeted processing of LC-MS data The MStractor workflow performs the following:
- Feature extraction (m/z-retention-time pair) using XCMS.
- Retention time alignment of the detected features across the samples composing the analytical set.
- Recognition and annotation of isotope clusters, fragments and charge states using CAMERA.
- Molecular feature filtering based on multiple criteria and conservative usage of intensity thresholds for maximum sensitivity.
- Creation of a data matrix summarizing the data processing results.
MStractor shows some additional features such as:
- Parameterization based on user provided inputs obtained from instrument specifications and reference measurements.
- Graphical tools for real-time quality monitoring and optimization of the feature extraction process
All the instructions are included in the script
A case study to test the script is available. The LCMS data set (.mzXML), contained in the folder MStractor_example is an example dataset containing 2 different treatments and pooled sample replicates.
The workflow was developed by the Metabolomics South Australia team at The Australian Wine Research Institute. Funding has been provided by Bioplatforms Australia (BPA) under the National Collaborative Research Infrastructure Strategy (NCRIS)
- Smith, C.A. and Want, E.J. and O'Maille, G. and Abagyan,R. and Siuzdak, G.: XCMS: Processing mass spectrometry data for metabolite profiling using nonlinear peak alignment, matching and identification, Analytical Chemistry, 78:779-787 (2006)
- Ralf Tautenhahn, Christoph Boettcher, Steffen Neumann: Highly sensitive feature detection for high resolution LC/MS BMCBioinformatics, 9:504 (2008)
- H. Paul Benton, Elizabeth J. Want and Timothy M. D. Ebbels Correction of mass calibration gaps in liquid chromatography-mass spectrometry metabolomics data Bioinformatics, 26:2488 (2010)
- Kuhl, C., Tautenhahn, R., Boettcher, C., Larson, T. R. and Neumann, S. CAMERA: an integrated strategy for compound spectra extraction and annotation of liquid chromatography/mass spectrometry data sets. Analytical Chemistry, 84:283-289 (2012)