Figure 1: rFnBP-A D1-4 ligand-binding and serum titre ELISA’s. A: increasing concentrations of purified rFnBP-A D1-4 were exposed to BSA (closed symbols) or human fibronectin (open symbols) -coated wells and detected using the p-nitrophenyl phosphate system from Sigma. B: Serum titre ELISA using rFnBP-ABCD476-838 (open symbols) and BSA (closed symbols) -coated wells exposed to two fold serial dilutions of rabbit pre-immune serum (diamond symbols), rFnBP D1-4 post-immune serum (square symbols), and an IgG purified fraction of post-immune serum (triangle symbols). All assays were performed in triplicate and values represent the mean absorbance at 405 nm (A405) with the standard error (error bars are shown in black on all graphs, but are difficult to see in some cases on account of the errors being small).