An improved medium for Plasmodium chabaudi in vitro erythrocyte invasion assays

RPMI-1640 is routinely used as the basal medium for the in vitro maintenance of malaria parasites. In this study we tested several commercially available nutritional media in a Plasmodium chabaudi chabaudi erythrocyte invasion assay and showed that three media, BME Basal Medium--modified, Dulbecco's Modified Eagle Medium, and William's Medium E, improved the level of merozoite invasion when compared with RPMI-1640. These media improve the rate of maturation of newly invaded rings to young trophozoites. Radioisotope incorporation by trophozoites maintained in these three media was also improved when compared to trophozoites maintained in RPMI-1640. BME Basal Medium--modified, or a combination of three parts BME Basal Medium--modified with one part William's Medium E, supported higher levels of erythrocyte invasion by merozoites. We suggest that either of these media replace the currently used RPMI-1640 for in vitro studies on P. c. chabaudi.