Abstract: The present invention relates to an improved method for comparing two or more samples containing proteins. This invention consists in first correlating and selecting the huge amount of data generated by mass spectrometry (PMF and MS/MS) before any kind of protein identification process, and then only identifying the proteins that are differentially expressed in dissimilar proteomes and thus have a potentially important biological interest. To do so, the experimental data resulting from separation and mass spectrometry are first correlated according to a correlation method, and then selected according to specific selection criteria. At this stage only, the selected data are analysed to identify the corresponding proteins.

Abstract: A method for identifying peptides and proteins, starting from corresponding tandem spectrometry data. A structured representation is matched with a biological sequence database, and the best peptide match or matches within the database is determined. MS/MS data is interpreted and structured to allow full exploitation of the information contained in the data during matching of the structured data with a biological sequence database.