A sodium dodecyl (lauryl) sulfate method was evaluated for the preparation of blood specimens and bone marrow aspirates for use in two amplification procedures (Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test [AMTDT] and Roche Amplicor M. avium/M. intracellulare [MAI] Test) for the detection and identification of Mycobacterium tuberculosis and M. avium and M. intracellulare, respectively.