Objective To obtain the polypeptides specifically binding to gastric cancer BGC823 cell from a Ph.D-12 TM phage display peptide library (PDPL), to search the markers of gastric cancer for early diagnosis and treatment. Methods The gastric cancer BGC823 cell was used as the antigen and the immortalized gastric epithelial GES cell was used as control for 3 rounds subtraction biopanning from PDPL at room temperature. The positive and specific binding clones were identified by cell enzyme-linked immunosorbent assay (ELISA) and immunochemistry staining. Those DNA sequences of identified clones were sequenced, polypeptides were marked by fluorescein FITC peptide tag, and polypeptides affinity and specificity of gastric cancer cells and tissues were identified. Results After 3 rounds of panning, 20 phage clones were identified by ELISA, one of which （GC-11） was specially binding to the BGC823. Cell and tissue immunofluorescence assay further presented a high affinity of fluorescein-labeled peptide FITC-GC-11 with BGC823 and gastric cancer tissue.Conclusion A peptide GC-11 which is specific binding to gastric cancer BGC823 cell and gastric cancer tissue has been selected from PDPL.
