Patent ID: 7723487

Claim:
A method for producing an antibody that binds cancer specific Proliferating Cell Nuclear Antigen (csPCNA), comprising: (A) obtaining a tissue or body fluid sample comprising csPCNA; (B) contacting said sample with a peptide comprising the amino acid sequence LeuLysGlnLeuAspAlaGlnGlnThrGlnLeuArgIleAspSerPhePheArgLeuAlaGlnGlnGluLysGluAspAlaLysArg (SEQ ID NO:1), wherein said peptide is immobilized on a solid support and binds to said csPCNA to form a peptide-csPCNA complex; (C) isolating csPCNA from said peptide-csPCNA complex so as to purify said csPCNA; and (D) producing an antibody using said csPCNA isolated from said peptide-csPCNA complex.