Detection of Mycobacterium tuberculosis DNA in clinical samples by using a simple lysis method and polymerase chain reaction.

We have evaluated the polymerase chain reaction for detection of Mycobacterium tuberculosis in clinical samples from patients with tuberculous infection. Two simple methods for mycobacterial DNA release have been compared: sonication and lysis with nonionic detergents and proteinase K. The more effective method was the enzymatic technique. By using this protocol with 75 specimens we detected M. tuberculosis DNA in all of the samples, whereas only 48 and 71 samples were positive by acid-fast staining and culture, respectively.