Twenty to thirty percent of causative agents of the respiratory tract infections are still unknown, that can be related to the lack of suitable laboratory procedures. Some of these organisms may cause progressive infection such as encephalitis and cardiac complications.

To recognize the M. pneumoniae , PCR-hybridization technique was used and a specific internal probe was produced for this organism using DNA-recombinant technology. After optimizing the test, technique was evaluated with 106 throat swabs. Obtained results showed 4 amplified specimens by PCR was positive using agarose gel electrophoresis, but thirty was positive by PCR-hybridization.