Sample preparation for Chlamydia pneumoniae PCR.

Fifty-three clinical specimens taken from the retropharyngeal mucosa of patients with longstanding respiratory tract infections were analyzed by polymerase chain reaction using two different methods for sample preparation. All specimens were divided into two aliquots, one treated with proteinase K, and the other with the Amplicor sputum sample preparation kit. All tests were run in parallel, employing a primer pair specific for Chlamydia pneumoniae. Of the samples prepared with the Amplicor kit 20.8% were found to be positive, as compared to 7.5% of the samples prepared with proteinase K. The outcome of C. pneumoniae PCR was improved by treatment involving a more complete lysis of cells derived from the specimen.