FIG. 6.
Binding inhibition assay to demonstrate surface exposure of PlpA. Decreasing titers of Rlow were incubated with preimmune rabbit serum IgG (stippled bars) and with anti-PlpA IgG (striped bars) and then exposed to immobilized fibronectin in microtiter plates. Bound organisms were detected by chicken anti-Rhigh, followed by horseradish peroxidase (HRP)-conjugated goat anti-chicken. At each titer, a significant difference (*) (P < 0.02) in the level of colorimetric signal (o-phenylenediamine) generated was observed.