Slides coated with Pf sporozoites were dried at RT for 30 minutes, fixed with 100% acetone at 4uC for 10 minutes, washed 2 times in PBS-0.05% Tween 20, dried carefully and blocked with 20 mL/ well of PBS-3% bovine serum albumin (BSA) for 30 minutes at RT. Slides coated with Pf merozoites were fixed with 100% acetone at 220uC for 15 minutes and dried O/N at RT. The appropriate antibody or serum dilutions prepared in PBS-3% BSA were distributed (10 mL/well) and incubated for 1h at RT in a humid chamber. After washing with PBS-0.05% Tween-20, goat anti-human or goat anti-mouse polyvalent immunoglobulins conjugated to Cy3 (Molecular Probes) diluted 1/500 in PBS-3% BSA or anti-human IgG (Fc specific) FITC conjugate (Sigma) diluted 1/50 in Evans blue solution (1/50000) was added (400 mL/slide) and incubated for 1h at RT in a humid chamber in the dark. Slides were washed as above, covered with 50 % glycerol, sealed and read using a fluorescence microscope (Leica DMIRB DC200).