Figure 4

Localization of PfM1AAP and PfM17LAP in intra-erythrocytic P. falciparum 3D7 trophozoite-stage parasites. Immunofluorescence assays were carried out using air-dried blood smears fixed with 75% acetone and 25% methanol at − 20 °C for 5 min, or 50% ethanol and 50% methanol at − 20 °C for 2 min, or 4% PFA and 0.0075% glutaraldehyde for 20 min at room temperature. Fixed parasites were probed with polyclonal antibodies against (A) PfM1AAP and (B) PfM17LAP. Specific aminopeptidase staining (green, Alexa-Fluor 488) was observed in the cytosol of parasites. Parasite nuclei were visualized using DAPI (blue; 4,6-diamidino-2-phenylindole) and monoclonal antibodies against the DV marker plasmepsin I (α-plasmepsin I, red, Alexa-Fluor 594) were used as a control. Differential interference contrast (DIC) and α-plasmepsin I with DIC are shown for reference. Scale bar, 3 µm.