Non-targeted tracer fate detection
NTFD is a Qt4 based software for the detection of stable isotope labeled metabolites in a non-targeted way. For this purpose, NTFD features a fully automatic data analysis pipeline starting with raw gas chromatography coupled to mass spectrometry (GC-MS) data derived from a stable isotope tracer experiment and ending in the determination of mass isotopomer distributions (MIDs) for all labeled ions.
NTFD is able to import GC-MS data in netCDF format and export the generated information into a tab-separated format. The software is implemented in the object orientated language C++ and is freely available for Linux and Windows operating systems in our download section.
The software provides the following features:
Interface: NTFD provides an easy-to-use graphical user interface with four main windows: the total ion current (TIC) chromatogram, a table of the labeled compounds, the spectra and the reference spectrum, respectively.
Chromatogram deconvolution: NTFD ionchromatograhically deconvolutes the GC/MS data. This step is required for the extraction of pure mass spectra and the detection of all compounds present in a chromatogram.
Compound pairing: NTFD automatically pairs the labeled with the unlabeled compound and calculates the integrated difference spectrum.
Mass isotopomer distribution (MID) calculation: NTFD automatically determines the MIDs for all detected and labeled fragments.
Statistical evaluation: If replicates have been provided, NTFD determines the 95% confidence intervals and the coefficients of determination (R2) for all MIDs.
Compound identification: In combination with a GC-MS reference compound library the program is able to identify the detected compounds, if present in the library. The reference library can for example be created with the MetaboliteDetector software.
Result output: NTFD is able to export all information into a tab-separated format (tsv). The list includes the MID, retention time (RT), 95% confidence intervals and the coefficients of determination (R2) for each detected and labeled ion. For further analysis, common spreadsheet applications (OpenOffice Calc, MS Excel, ...) or statistical tools (Gnu R, ...) can be used.
How to cite:
Hiller, K.; Wegner, A.; Weindl, D.; Cordes, T.; Metallo, C.M.; Kelleher, J.K.; Stephanopoulos, G. NTFD--a stand-alone application for the non-targeted detection of stable isotope-labeled compounds in GC/MS data. Bioinformatics, 2013, 29(9), 1226-8 [ Pubmed ]
Hiller, K.; Metallo, C. M.; Kelleher, J. K. & Stephanopoulos, G. Nontargeted elucidation of metabolic pathways using stable-isotope tracers and mass spectrometry. Anal Chem, 2010, 82, 6621-6628. [ Pubmed ]top
technical support: Nils koschnitzki
Braunschweig Integrated Centre of Systems Biology (BRICS)