A new technique for drug susceptibility tests for Plasmodium falciparum by ethidium bromide fluoroassay.

When Plasmodium falciparum parasites were stained with the fluorescent dye ethidium bromide, the fluorescence intensity of the solubilized parasites was correlated with the amount of nucleic acid present. It was possible to monitor development of the parasites from ring form to schizont by the fluoroassay. The assay system was applied to in vitro drug susceptibility tests on malaria parasites.