MSiMass list: A public database of identifications for protein MALDI MSI.

The clinical application of mass spectrometry imaging has developed into a sizeable sub-discipline of proteomics and metabolomics because its seamless integration with pathology enables biomarkers and biomarker profiles to be determined that can aid patient and disease stratification (diagnosis, prognosis and response to therapy). Confident identification of the discriminating peaks remains a challenge owing to the presence of non-tryptic protein fragments, large mass-to-charge ratio ions that are not efficiently fragmented via tandem mass spectrometry or a high density of isobaric species. To aid the clinical development and implementation of mass spectrometry imaging a public database of identifications has been initiated. The MSiMass list database (www.maldi-msi.org/mass) enables users to assign identities to the peaks observed in their experiments and provides the methods by which the identifications were obtained. In contrast to existing protein databases, this list is designed as a community effort without a formal review panel. In this concept, authors can freely enter data, and can comment on existing entries. In such, the database itself is an experiment on sharing knowledge and its ability to rapidly provide quality data will be evaluated in the future