Parasite cultures were enriched for erythrocytes infected by late trophozoite/schizont-stage parasites by exposure to a strong magnetic field (Paul et al., 1981; Staalsoe et al., 1999) . Protein extracts of purified IEs were prepared with 2% SDS in PBS containing complete protease inhibitor (Roche, VAR2CSA-specific IgG in pregnancy-associated malaria 343