06 RDF Metabolights Resource Module
The ISATab-converted RDFified Metabolights Sandbox resource describes the ISA-files from metabolights ontologically, courtesy of The European Bioinformatics Institute(EBI), The European Molecular Biology Laboratory(EMBL) and The University of Oxford.
The ISAtab-file format is a file-format consisting of three basic layers of information:
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Investigation file: A metadata file that describes the overall project and/or the high-level context of the experiments in the studies and assays.
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Study files: A file that describes a specific context of research. Must be assigned to an investigation file.
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Assay files: Files that describe analytical measurements in context of their assigned study.
Since this project mainly handles mass spectrometry experiments, there is another type of file that is not described in the base ISAtab specification, but is endorsed by the team behind isatools: .maf(metabolite assignment files) These files contain assay data specific to mass spectrometry experiments.
A more in-depth explanation of the ISA file format can be found on the isatab site: http://isatab.sourceforge.net/format.html
The ISA ontology we constructed is a much simpler and much less descriptive alternative to the existing isaterms model, starting with the fact that it is only described in RDF, omitting the OWL-DL layer. This graph contains a specification for the .maf-file that we need for mass spectrometry and also provides a way to directly link these maf files to ChEBI. As it is only a partial ontological representation of the ISA file format, there is no planned long-term use, it just provides a conceptual way of linking Metabolights mass spectrometry experiments (specifically the metabolites used) to ChEBI.
The design of the resource is to use the local ISA ontology, but allows to swap to use the ontological specification to the isaterms ontology at a later stage.
