Scanning electron microscopy and ektacytometry analysis of immature and mature P falciparum GIEs. (A) Scanning electron microscopy images of Plasmodium falciparum GIEs (B10 clone) from stage II to stage V of maturation. Bars represent 1 μm. (B) Giemsa staining images of stage II/III (top panel) and stage V (bottom panel) GIE samples used in ektacytometry analysis. (C) Response to increasing shear stress of erythrocytes infected by P falciparum stage II/III (red line) and stage V (blue line) gametocytes (40% parasitemia) and of uninfected erythrocytes (green line). Error bars represent SE. (D) Ratios of EIs of infected versus uninfected erythrocytes calculated from the 3- to 9.49-Pa range of shear stresses in the ektacytometry analysis (C) showing a statistically significant difference between immature and mature GIEs (Mann-Whitney rank-sum test, P = .0004).