Upper panel: A 3D7-PM2 trophozoite was labelled with BODIPY® ceramide and the GFP (green fluorescence) and BODIPY® (red fluorescence) signals were imaged by confocal microscopy. The images shown represent an average projection obtained from a series of optical sections. BODIPY® ceramide labels the membrane rich parasite cytoplasm as well as punctate structures in the RBC cytosol that have previously been shown to be Maurer’s clefts and other membranous compartments. The cytostomal vesicles are visible as apparently independent structures in the parasite cytoplasm.

Lower panel: Mixed-stage transfected parasites were incubated with the pH probe, LysoSensor Blue. Shown are bright field, LysoSensor Blue, GFP and merged GFP/LysoSensor Blue images. The LysoSensor Blue fluorescence is largely associated with the DV, while the GFP chimaera is also present in cytostomal vesicles (arrows) that do not stain with the LysoSensor Blue. Scale bar, 2 μm.

Klonis N, Tan O, Jackson K, Goldberg D, Klemba M, Tilley L. Evaluation of pH during cytostomal endocytosis and vacuolar catabolism of haemoglobin in Plasmodium falciparum. Biochem J. 2007 407(3):343-54.