Cloning and Prokaryotic Expression of ag85b Gene of Mycobacterium Bovis

To clone and express the geneen coding Mycobacterium tuberculosis antigen Ag85B,a pair of specific primers were designed,the Ag85B gene was amplified from the genomic DNA by PCR,and cloned into vector PET28a(+) to construct the recombinant plasmid.The recombinant plasmid was transformed into the expression vector Escherichia coli BL21(DE3),and induced with IPTG;the presence of the recombinant protein in the expression vector was analysed by SDS-PAGE and Western blot.Results showed that the ag85b gene was successfully expressed with expected 33 ku in molecular weight.It can be specifically recognized by His McAb.