T. vaginalis surface immunofluorescence by monoclonal antibody (mAb) 6B8 and immunoblot detection of a trichomonad protein. A. Fluoresceine isothiocyanate- conjugated goat anti-IgA antibody reacts with the surface of non-permeabilized T. vaginalis (A1), T. foetus (A2), and T. tenax (A3) incubated with IgA mAb 6B8. Brightfield microscopy is provided below the fluorescence panels to illustrate the integrity of the organisms. Fluorescence experiments were performed at least 5 times, and the distinct patchy pattern of fluorescence for T. tenax contrasted with the similar overall surface fluorescence for T. vaginalis and T. foetus. B. Total proteins of 107 trichomonads of T. vaginalis (lane 1), T. foetus (lane 2), and T. tenax (lane 3) were separated on 10% polyacrylamide gels by SDS-PAGE prior to blotting onto Hybond-P™ membranes. Blots were probed with mAb 6B8. Molecular weight of the protein is indicated in kilodaltons (kDa) (×1000).