Synchronization ofPlasmodium yoelii nigeriensis andP. y. killicki infection in the mouse by means of Percoll-glucose gradient stage fractionation: Determination of the duration of the schizogonic cycle

Abstract
The youngest (rings and young trophozoites) erythrocytic stages ofPlasmodium yoelii nigeriensis andP. yoelii killicki, two rodent malaria subspecies developing very asynchronously in the blood, were separated from the other stages using a discontinuous Percoll-glucose gradient. They were inoculated into mice and the subsequent infection remained synchronous for two generations. The duration of the asexual cycle was found to be 18 h.