Identifying proteins via Proteomics-Mass Spectrometry. The mixture of proteins (or just one protein) must be digested to obtain peptides. The resulting peptides have to be cleaned and desalted via chromatography (e.g. POROS R2) to avoid salts and detergents, which artefact the MS analysis. Subsequently, the desalted and cleaned peptides are injected into the mass spectrometer. Finally, the matched peptides allow the identification of the proteins using databases (e.g. Mascot Server).