Favourable effect of detergent on antigen detection and comparison of enzyme linked detection systems in an ELISA for Chlamydia trachomatis.

The influence of addition of detergents to the antigen on sensitivity of an ELISA for the detection of Chlamydia trachomatis was investigated. Of the detergents tested, only octyl-beta-d-glucopyranoside and sodiumdesoxycholate gave respectively a two- to fourfold and an eightfold increase in sensitivity. The effect was only present within a narrow range of detergent concentrations. The optimal detergent concentration was strongly dependent on the protein concentration in the antigen preparation. For optimal detection of the bound chlamydial antigen, enzyme and biotin labeled secondary antibodies were compared. The biotin labeled antibodies were combined with enzyme labeled streptavidin-biotin complex (SBC). Color development was obtained with both types of conjugates by using either o-phenylenediamine (OPD) or an enzyme amplification system. The best results were obtained with the SBC method and OPD.