Abstract: Objective To clone and express recombinant CFP10-ESAT6 fusion protein and CFP32 protein ofMycobacterium , and analyze their antigenicity.  Methods The cfp10-esat6 fusion gene fromMycobacterium tuberculosisstrain H37Rv was amplified by PCR. DNA fragment encoding CFP32 fromMycobacterium bovisBacillus Calmette-Guerin（BCG） was obtained by PCR. After cloning and sequence analysis, the cfp10-esat6 fusion gene and cfp32 gene were subcloned into expression vector pQE-30 and pET-23a(+), respectively. The recombinant proteins were expressed inE.coliBL21, purified by affinity chromatography, and analyzed by SDS-PAGE. Their antigenicities were analyzed by Western blot and indirect ELISA.  Results Recombinant expression plasmid pQE30-cfp10-esat6 and pET-cfp32 were constructed. The recombinant CFP10-ESAT6 fusion protein and CFP32 protein were expressed inE.coliBL21 and were purified by affinity chromatography. The purified CFP10-ESAT6 and CFP32 proteins were used to detect the antibodies against tuberculosis, their sensitivities were 85.7% and 71.4%, respectively, their specificities were all 100%.  Conclusion s Recombinant CFP10-ESAT6 fusion protein and CFP32 protein with good antigenicity were successfully obtained.

Key words: Mycobacterium tuberculosis, recombinant fusion proteins, bacterial proteins