An immune dot-blot test for the diagnosis of ocular infection with Chlamydia trachomatis

We report a new simple non culture technique for the diagnosis of chlamydial eye disease. The immune dot-blot test (IDBT) detects chlamydial lipopolysaccharide (LPS) antigen which, after being trapped on nitrocellulose membrane, is detected by autoradiography with 125I-labelled genus specific monoclonal antibody. This test was evaluated over a two year period in adults and neonates, by comparing it to culture, serological detection of chlamydial antibodies and clinical features. We demonstrate that the IDBT is more than twice as sensitive as culture, and suggest that in order to achieve a reliable diagnosis of chlamydial eye infection an immunological test for chlamydial antigen should be used in preference to tests which detect the organisms themselves.