Chlamydia pneumoniae elementary body antigenic reactivity with fluorescent antibody is destroyed by methanol

Methanol, used for fixing chlamydia organisms to microscopic slides, was shown to eliminate the antigenic reactivity of Chlamydia pneumoniae elementary bodies with fluorescent antibodies. Acetone fixation had no adverse effect. Chlamydia trachomatis and Chlamydia psittaci were not affected by methanol fixation. The effect of methanol on C. pneumoniae is another characteristic that differentiates this species from the other two chlamydia species.