Patent ID: 7851742
Filing Date: 2010-12-14
Classification: G01N,G16B,H01J

Abstract:
1. A method for identifying proteins in a mixture, comprising: digesting the mixture to obtain a peptide mixture; applying the digested mixture to an LC/MS system; applying a low-energy mode in the mass spectrometer portion of the LC/MS system; applying a high-energy mode in the mass spectrometer portion of the LC/MS system to fragment peptide precursors derived from the peptide mixture; obtaining mass information and retention time information from peptide precursor data acquired from the peptide precursors during the low-energy mode; obtaining mass information and retention time information from fragment data acquired from the fragmented peptide precursors during the high-energy mode; selecting a target peptide from a database of proteins; determining a mass associated with a target precursor associated with the target peptide; determining a mass associated with each Y- and B-ion corresponding to the target precursor; comparing the mass associated with the target precursor, and the masses associated with the Y- and B-ions to the mass information related to the peptide precursor data and fragment data; detecting mass matches resulting from the comparisons; determining retention times of mass matches; and identifying whether the target peptide is present in the peptide mixture based on the detected mass matches and retention times of detected mass matches.