Fig. 1

Cell permeability of VSG dye. a Giemsa-stained thin blood smear of the non-synchronized culture revealed mixed developmental stages of falciparum malaria parasites. Scale bars: 10 µm. b Laser scanning confocal microscopic images of P. falciparum-infected erythrocytes uptaking VSG (upper and middle panels). Differential interference contrast images are shown (far left panel). VSG was activated by a 488-nm argon-ion laser, and is displayed as green in the middle panel. Differential interference contrast and fluorescent images are merged in the far-right panel. Yellow and blue arrows indicate low and high intensity of VSG, respectively. The unstained, P. falciparum-infected erythrocytes were used as a control. Scale bars: 50 µm at upper and 10 µm at middle and lower panels. R, ring form; Tro, trophozoite; Sch, schizont; DIC, differential interference contrast; VSG, ViSafe Green