MOWSE (for MOlecular Weight SEarch) is a method for identification of proteins from the molecular weight of peptides created by proteolytic digestion and measured with mass spectrometry.[1] The MOWSE algorithm was developed by Darryl Pappin and David Perkins at the Imperial Cancer Research Fund, and licensed from Cancer Research Technology. The probability-based MOWSE score formed the basis of development of Mascot, a proprietary software for protein identification from mass spectrometry data. It is documented here