Patent ID: 7422865

Claim:
A method for identifying proteins in a proteomic sample comprising the steps of: a. providing a mixture of proteins; b. protecting terminal amino or carboxy groups of the proteins with a protecting agent; c. selectively protecting side chain amino or carboxyl groups of the proteins with a second protecting agent; d. cleaving the protected proteins with a cleaving agent, thereby producing a peptide mixture of: (i) terminally protected peptides; and (ii) non-terminally protected peptides comprising free terminal amino and carboxyl groups corresponding to the cleavage sites; e. separating the terminally protected peptides from the peptide mixture, thereby reducing the sample complexity to one peptide per sample protein, wherein said separating step e comprises: (i) selectively covalently bonding the free terminal amino group of the non-terminally protected peptides to a solid support, washing said solid support with a solvent and collecting those solvent fractions containing the terminally protected peptides; or (ii) wherein the protecting agent of the terminally protected peptides contains a reactive group that can form a covalent bond with a solid support, and selectively covalently bonding the reactive group of the protecting agent to a solid support, washing said solid support with a solvent and releasing the terminally protected peptides from said solid support; and f. detecting the terminally protected peptides.