AIM:To construct a phage display library of human single-chain variable fragment (scFv) antibodies associated withesophageal cancer and to preliminarily screen a scFvantibody against esophageal cancer.METHODS:Total RNA extracted from metastatic lymphnodes of esophageal cancer patients was used to constructa scFv gene library.Rescued by M13K07 helper phage,thescFv phage display library was constructed,esophagealcancer cell line Eca 109 and normal human esophagealepithelial cell line (NHEEC) were used for panning andsubtractive panning of the scFv phage display library toobtain positive phage clones.Soluble scFv was expressedin E.coli HB2151 which was transfected with the positivephage clone,then purified by affinity chromatography.Relative molecular mass of soluble scFv was estimated byWestern blotting,its bioactivity was detected by cell ELISAassay.Sequence of scFv was determined using the methodof dideoxynucleotide sequencing.RESULTS:The size of scFv gene library was approximately9×10~6 clones.After four rounds of panning with Eca109and three rounds of subtractive panning with NHEEC cells,25 positive phage clones were obtained.Soluble scFv wasfound to have a molecular mass of 31 ku and was able tobind to Eca109 cells,but not to HeLa and NHEEC cells.Variable heavy (V_H) gene from one of the positive cloneswas shown to be derived from the γ chain subgroup Ⅳ ofimmunoglobulin,and variable light (V_L) gene from the κchain subgroup Ⅰ of immunoglobulin.CONCLUSION:A human scFv phage display library canbe constructed from the metastatic lymph nodes ofesophageal cancer patients.A whole human scFv againstesophageal cancer shows some bioactivity. AIM: To construct a phage display library of human single-chain variable fragment (scFv) antibodies associated with withesophageal cancer and to preliminarily screen a scFv antibody against esophageal cancer. METHODS: Total RNA extracted from metastatic lymphnodes of esophageal cancer patients was used to constructa scFv gene library. Rescued by M13K07 helper phage, the scFv phage display library was constructed, esophageal cancer cell line Eca 109 and normal human esophagealepithelial cell line (NHEEC) were used for panning and screening panning of the scFv phage display library toobtain positive phage clones. soluble scFv was expressedin E. coli HB2151 which was transfected with the positive phage clone, then purified by affinity chromatography. Relative molecular mass of soluble scFv was estimated by Western blotting, its bioactivity was detected by cell ELISA assay. Sequence of scFv was determined using the method of dideoxynucleotide sequencing .RESULTS: The size of scFv gene library was approximately9 × 1 0 to 6 clones. After four rounds of panning with Eca109 and three rounds of subtractive panning with NHEEC cells, 25 positive phage clones were obtained. Soluble scFv was found to have a molecular mass of 31 ku and able to tobind to Eca109 cells, but not to HeLa and NHEEC cells. Variable heavy (V_H) gene from one of the positive clones was shown from be derived from the γ chain subgroup Ⅳ of immunoglobulin, and variable light (V_L) gene from the κchain subgroup Ⅰ of immunoglobulin. CONCLUSION: A human scFv phage display library canbe constructed from the metastatic lymph nodes of esophageal cancer patients. A whole human scFv againsophageal cancer shows some bioactivity.