Patent ID: 6962818

Claim:
A method for sequencing a terminal portion of an oligomer, comprising: (a) contacting said oligomer with a mass defect labeling moiety to covalently attach the mass defect labeling moiety to a terminus of the oligomer and form a labeled oligomer, said mass defect labeling moiety comprising at least one element having an atomic number from 17 to 77; (b) fragmenting said labeled oligomer using an enzymatic, chemolytic or mass spectrometric fragmentation method to produce labeled oligomer fragments; (c) identifying a mass spectrum data corresponding to said labeled oligomer fragments; and (d) determining the sequence of at least two terminal residues of said labeled oligomer, wherein said sequence determination step comprises discriminating between the mass of the labeled oligomer fragment and an unlabeled oligomer fragment based on the nuclear binding energy of the mass defect labeling moiety; wherein said oligomer is selected from the group consisting of a protein, polysaccharide, nucleic acid, and lipid.