Anti-caveolin-2 antibodies do not cross-react with chlamydial EBs. C. trachomatis serovar K and C. pneumoniae AR39 EBs were purified by renografin gradient and separated on a 10–12% NuPAGE gel. The proteins were transferred to a PVDF membrane, (A) stained with a mouse monoclonal anti-caveolin-2 antibody and the reacting complex detected with an AP-conjugated goat-anti-mouse secondary antibody. Mw is the molecular weight marker, Con is an endothelial cell lysates for caveolin-2 control, Cpn is C. pneumoniae EBs and Ct represents C. trachomatis EBs. Note that there is staining in the control lane at 22 kDa (caveolin), while there is no staining in the chlamydial organism lanes. (B) control blot using the same quantity and preparation of C. trachomatis serovar K and Cpn EBs as above. The blot was stained with a rabbit anti-Chlamydia polyclonal antibody.