Chlamydia pneumoniae PCR is a molecular diagnostic technique that utilizes polymerase chain reaction (PCR) to detect the presence of Chlamydia pneumoniae, a bacterium known to cause respiratory tract infections presenting with atypical pneumonia, bronchitis, and upper respiratory tract infections. A test involves amplification of chlamydia genetic structure, extension using DNA polymerase, and producing copies of the target sequence to diagnose and treat specifically.