Objective: Polymerase chain reaction (PCR) is a molecular technique whose accuracy is determined by the choice of the target DNA and definition of the primers within the DNA sequence. Thus, we evaluate the performance of different genes specific for mycobacterium tuberculosis complex in sputum samples obtained from suspected cases of pulmonary tuberculosis. Methods: One hundred and fifty samples were processed for detection of mycobacterium tuberculosis by ZN smear examination, culture on LJ medium and PCR was performed with specific primers for the following targets IS6110, MPB64 and 38kDa. Results: Each PCR test was found to have a much higher sensitivity than conventional test. Among all gene targets tested, the primer specific for amplifying the 123bp of IS6110 gene and 240bp of MPB64 gene gave the highest sensitivity of 95.7% and 97.8% respectively and 419bp of 38kDa gene gave 93.47%. Conclusion: PCR has a great potential to improve the clinician ability to diagnose tuberculosis especially targeting MPB64 gene and IS6110 gene.
