Abstract: Objective To determine the feasibility of the microfluorimetric assay (MFA) in screening antimalarial drugs. Methods The dose-response curves and effective concentration that resulted in a 50% inhibitory of parasitemia (IC₅₀ ) of chloroquine, artemisinin, artemether and pyronaridine phosphate against Plasmodium falciparum strain FCC1/HN cultured in vitro were tested by microfluorimetric assay (MFA) and compared with those determined by microscopy-based assay. Results The IC₅₀ of chloroquine, artemisinin, artemether and pyronaridine phosphate were 18.79, 6.32, 3.67 and 2.00 nmol/L by MFA and the IC₅₀ of which were 19.65, 5.82, 4.38 and 2.83 nmol/L by microscopy-based technique respectively. The results from both techniques were similar or identical (P>0.05). Conclusion The microfluorimetric assay (MFA) is sensitive, rapid, easily interpreted and would be useful for testing the sensitivity of Plasmodium falciparum to antimalarials and for screening drugs.

Key words: Antimalarials, Plasmodium falciparum, Drug screening, Microfluorimetric assay