Fractionation of Plasmodium chabaudi-infected erythrocytes into parasites and ghosts.

We have developed a new procedure for subfractionation of Plasmodium chabaudi-infected erythrocytes into parasites and ghosts. Trophozoite-infected erythrocytes enriched over a percoll-step (:1.10 g/cm3) are subjected to a glycerol-enhanced osmotic shock. This induces the release of parasites and the emergence of erythrocyte ghosts, which can be separated on a continuous percoll gradient (:1.02----1.10 g/cm3). The parasites are intact in terms of ultrastructure and incorporation of 14C-isoleucine. The erythrocyte ghosts are purified over a two-step percoll gradient (:1.01-1.02 g/cm3). Our method recovers about 40%-50% of the initial ghosts and 70%-95% of the initially freed parasites.