Figure 1

Double filtration of A1-H.1 P. knowlesi E64-arrested schizonts isolates merozoites of high purity. (a) Representative flow cytometry plots showing different cell populations, pre and post filtration. Plots do not show uninfected RBCs (y-axis has been cropped to give better resolution of free merozoite populations). Figure S3 shows uncropped RBC population. Free merozoite population was tightly-gated after identification of haemozoin-derived events (Fig. S1). (b) Double-filtration increases the merozoite:late-stage ratio significantly, giving a free merozoite preparation of high purity. Graph shows mean from n = 9 experiments. Error bars represent SEM. P-values comparing different merozoite:late-stage ratios represent one-way multiple comparisons ANOVA test (**P < 0.01). (c) TEM image of free merozoites. Scale bars = 500 nm.