The detectability of mycobacterium in culture by non-isotopic, chemiluminescent DNA probes for Mycobacterium tuberculosis (M. tuberculosis) and M. avium-intracellulare complex (MAC) was evaluated and compared with that by 125I-labeled DNA probe for the same mycobacteria. The sensitivity and specificity of the AE-DNA probes for MAC were 97.2% and 100%, respectively, for the conventional method and were both 100% for the 125I-labeled DNA probes. The detection limits of the AE-DNA probes tests for both M. tuberculosis and MAC were 10(5)-10(6) CFU/tube which were almost the same as those of the 125I-labeled DNA probes tests. Because the procedure is simple, rapid (it can be completed within 90 min), and safe (it does not use radioisotopes), it can be easily performed in any clinical laboratory.