<p>Effects of mAbs on immunoprecipitation of [<sup>35</sup>S]-labeled parasite culture supernatant containing labeled native EBA-175. Panel A shows that ratios of mAb R217 (against F2) and R218 (against F1) together increased the blocking of native EBA-175 binding (a synergistic effect). In contrast, Panel B shows that different ratios of mAb R217 (against F2) and R256 (also against F2) together resulted in similar levels of blocking (an additive effect). R217 and R256 may recognize a common epitope within the F2 domain. Bars show % blocking values as assessed by a phosphoimager.</p