Abstract: The α-antigen is one of the dominant mycobacterial protien and consists of three structurally related components which are designated as 85A,85B and 85C.We have reported the molecular cloning of 85A and 85B of M.leprae and its over production in E.coli.In order to screen an antigen with high specificity and immunnity for the serodiagnosis and explore the etiology of leprosy.We continue to study the construction of the 85C antigen of Mycobacterium leprae in E.coll.M.leprae 85C gene was amplified by PCR technique using primers 5′-terminus and 3′-terminus which contain BamH Ⅰ and Hind Ⅲ recognition sequence,respectively,and insert amplified fragment into expression vector. Ampicillin resistant transformats were cultured in LB medium and inducedby IPTG and M13T7pol to produce M.leprae 85C fusion protein.The recombinant 85C protein was recognized by anti-α-TB antisera.The result of this study will be useful for the further study of a-antigen.

Key words: Mycobacterium leprae, Antigen 85 complex