Sensitivity of immunofluorescence with monoclonal antibodies for detection of Chlamydia trachomatis inclusions in cell culture.

Monoclonal antibodies which recognize the species-specific major outer membrane protein antigen of Chlamydia trachomatis were used for immunofluorescence staining of chlamydial inclusions in cell culture. A total of 115 clinical specimens were inoculated onto replicate HeLa 229 cell monolayers and assayed for chlamydial inclusions by immunofluorescence staining and Giemsa staining. Of the isolates, 38 were detected by immunofluorescence staining on passage 1 and 1 was detected on passage 2; 23 isolates on passage 1 and 13 isolates on passage 2 were detected by Giemsa staining. Immunofluorescence staining was significantly more sensitive than Giemsa staining for detecting chlamydial inclusions, particularly from specimens containing low titers of Chlamydia.