Effect of pH on reactivity of monoclonal antibodies to Chlamydia.

The influence of pH on the reactivity of anti-Chlamydia monoclonal antibodies with genus-, species- and type-specific activity to chlamydial elementary body (EB) antigens was studied by solid-phase enzyme immunoassay. The antibodies bound readily to EB antigen from pH 4 to 9, but had a reduced binding efficiency at more extreme pH conditions. Antibodies although having a wide pH range of optimal binding, bound non-specifically at acidic pH (4-6). This non-specific binding was not seen with polyclonal guinea pig or rabbit anti-Chlamydia antibodies. Thus it seems to be a specific property of mouse immunoglobulins when tested against cell antigen.