Detection and discrimination of M. tuberculosis complex species and M. bovis bacillus Calmette-Guérin (BCG) by the use of a novel assay. Each lane contains a PCR product amplified from DNA of the following mycobacteria: BCG Pasteur, isolated from a patient (lane 1); BCG Tokyo, isolated from a patient (lane 2); BCG Pasteur 1173p2, vaccine (lane 3); BCG Tokyo 172, vaccine (lane 4); and isolates of M. tuberculosis (lanes 5 and 6), M. intracellulare (lane 7), M. avium (lane 8), and M. abscessus (lane 9). Lane NC represents a negative control, and lane M contains molecular size markers (100-bp ladder). The expected sizes of the PCR products are marked on the left, and the 720-bp internal control (IC) amplicon was detected in each test sample.