Plasmodium DNA fluoresces with berberine: a novel approach for diagnosis of malarial parasites.

The key to reducing mortality and morbidity associated with malaria is rapid diagnosis and early, effective therapy. Berberine, a plant alkaloid, has been used for fluorescent staining of the Y chromosome. We evaluated whether berberine can be used for staining of malarial parasites in 40 selected peripheral blood smears from patients with clinical symptoms of malaria; smears were evaluated with OptiMal (DiaMed, Miami, FL) and Giemsa stain. Twenty were positive with both OptiMal and Giemsa (Plasmodium vivax, 14; Plasmodium falciparum, 6); 10 were negative with both. The remainder were positive by OptiMal but negative by Giemsa and, therefore, were classified as equivocal. All slides were processed simultaneously, stained with berberine, and read under a fluorescent microscope. P vivax and P falciparum DNA fluoresced with berberine. The positives and negatives by berberine concurred with the Giemsa staining. Of the 10 equivocal smears, 5 were confirmed positive by berberine. Gametocytes were easily identifiable. This test has high sensitivity and high positive predictive value and, once standardized, can be used as a potential screening and diagnostic tool.