Detection of bound complement regulators by B. garinii ST4 PBi. After incubation of spirochetes with NHS-EDTA, bound proteins were eluted. The wash (w) and the eluate (e) fraction were separated by SDS-PAGE. The last wash and eluate fraction were subjected to SDS-PAGE and separated proteins were blotted on nitrocellulose. CFH and FHL-1 were visualised using a polyclonal goat anti-factor CFH antiserum (Calbiochem). It is shown that B. garinii ST4 PBi is able to bind FHL-1 on its membrane.