Use of polymerase chain reaction for detection of Chlamydia trachomatis

A polymerase chain reaction (PCR) assay was developed for detection of Chlamydia trachomatis DNA. From the published sequence of the common C. trachomatis plasmid, two primer sets were selected. Detection of amplified sequences was done by agarose gel electrophoresis of cleaved or uncleaved amplified sequences, Southern hybridization, or dot blot analysis. The PCR assay was optimized and, after 40 cycles of amplification with primer set II, demonstrated a sensitivity of 10(-17) g of DNA, which corresponds to the detection of one copy of the plasmid. Because of the high sensitivity, we developed a closed system in which airborne contamination was minimized. Analysis of 228 clinical samples tested by cell culture, IDEIA enzyme immunosorbent assay (Medico-Nobel, Boots-Celltech Ltd., Berkshire, United Kingdom), and PCR showed a sensitivity of 100%, a specificity of 93% when PCR was compared with cell culture, and a corrected specificity of 99% when PCR was compared with cell culture or IDEIA.