In vitroisolation ofPlasmodium knowlesimerozoites using polycarbonate sieves

Abstract

A culture chamber fitted with a polycarbonate sieve has been used to isolatePlasmodium knowlesimerozoites as they are released from schizonts. A 3 μm pore-size sieve allows passage of normal erythrocytes and red cells containing rings and trophozoites and can be used to concentrate schizonts from a mixed cell population. A 2 μm pore-size sieve retains normal and parasitized cells and provides uncontaminated merozoites in high yield (5 × 1010merozoites per ml schizonts). Merozoite viability diminishes rapidly during 30 min after isolation. These preparations should prove valuable for studies of the biochemical, physiological and antigenic properties of this transient extracellular phase of the malaria parasite.