Detection and Identification of Mycobacterium Tuberculosis, M. Bovis/BCG, and M. Avium by Two-step Polymerase Chain Reaction. Comparison with ELISA Using A60 Antigen

We propose a rapid two-step PCR to amplify a 767-bp sequence present in the gene coding for the 65-kD antigen of mycobacteria. The high G+C content (80%) permitted annealing to occur at 70 degrees C, enhancing the specificity. The amplified fragment contains a restriction site for differentiation between M. tuberculosis, M. bovis/BCG, and M. avium. Complete diagnosis can be achieved in less than four hours without labelled probe or nucleic acid transfer.