DNA fragment length polymorphism analysis of Mycobacterium tuberculosis isolates by arbitrarily primed polymerase chain reaction.

Strain identification of Mycobacterium tuberculosis would prove whether transmission had occurred between individuals. A method to characterize strains of M. tuberculosis has been developed utilizing polymerase chain reaction (PCR). Purified chromosomal DNA of cultured clinical samples of M. tuberculosis were subjected to PCR using short (10-12 nucleotide) oligonucleotide primers. PCR products visualized after agarose gel electrophoresis and ethidium bromide staining demonstrated that different strains of M. tuberculosis give different banding patterns. This technique was used to confirm the relationship between cases of tuberculosis in several clusters, prove the lack of relationship between 2 isolates with the same antibiotic-resistance pattern, confirm a suspected mislabeling event, and suggest the source of infection in a case of tuberculous meningitis. This method is rapid and simple and does not require radioactive probes.