Fig. 4. Specific antibody inhibition of PfRh2b function in 3D7, 3D7Δ2a1, 3D7Δ2b1 and D10. Assays measure the percentage merozoite invasion in the presence or absence of anti-PfRh2a/b IgG antibodies relative to controls with IgG from normal rabbit sera (NRS). The erythrocytes in each panel are: (A) untreated; (B) trypsin treated; (C) neuraminidase/trypsin treated; (D) chymotrypsin treated; and (E) trypsin/chymotrypsin treated. (F) Assays measure the percentage merozoite invasion into S-s-U^– erythrocytes that lack glycophorin B. Error bars in all cases show 95% confidence limits from 4–10 experiments in triplicate.