Direct detection of Mycobacterium tuberculosis in clinical specimens by DNA amplification.

A polymerase chain reaction assay was developed for the amplification of a 336-bp repetitive fragment in the chromosome of Mycobacterium tuberculosis. The assay is specific for M. tuberculosis and can be used to detect the amount of DNA present in less than 10 organisms. It was used to demonstrate M. tuberculosis DNA in 14 of 26 clinical specimens (from cerebrospinal fluids, pleural fluid aspirates and biopsies, pericardial fluid aspirates, and an open lung biopsy), and it was shown to be at least as sensitive as conventional culture techniques with these specimens.