Binding of merozoites to neutrophils. (A) Forward and side scatter flow cytometry analysis of merozoites, neutrophils, or a mixture showing gating of different CD16⁺ neutrophil populations. (B) Binding of merozoites opsonized with FITC-labeled MSP1₁₉-specific human IgG1, human IgA1, or mouse IgG2b (red traces), to total neutrophils (R1) or neutrophils in gate 2 (R2). Binding of merozoites opsonized with an isotype-matched control Ab shown by the black trace. (C) Mean fluorescence intensities of opsonized merozoites binding to R1-(□) or R2-gated neutrophils (▪). Error bars indicate standard deviation from the mean.