Concentration of Plasmodium falciparum-Infected Erythrocytes by Density Gradient Centrifugation in Percoll

The asynchronous growth of Plasmodium falciparum in vitro necessitates the development of procedures for the isolation of specific developmental stages of this important parasite for immunological, biochemical, and vaccination studies. Satisfactory procedures used in our laboratory have been discontinuous sucrose (Siddiqui et al., 1974, J. Parasitol. 64: 168-169) and BSA (Siddiqui et al., 1979, Bull. W.H.O. 57: 75-82) gradient centrifugation. Recently we have found Percoll, a commercially available product marketed by Pharmacia (Piscataway, New Jersey), to be an excellent medium for the isolation of