Abstract: ObjectiveTo construct and express the single chain Fv gene fragment for human CD₃ antigen and conduct imitation analysis on conformation.MethodsThe variable region gene of heavy chain(VH)and light chain(VK)of antiCD₃ antibody were linked into single chain Fv by splicing overlapping and extension(SOE)ScFv genes were cloned to pET28(a+)and expressed in E.coli.ResultsThe DNA sequence analyses and imitation of conformration analyses demonstrated that ScFv gene were 732bp,conformation steady.compatibility S>0.The ScFv fragment were expressed in BL21(DE3),and folded into 26.5 KD protein.ConclusionThe correct gene of anti-CD₃ Scfv was constructed.It would be used to construct the anti-CD₃/anti-HBV bifunctional antibody.