Fig. 7. Detection of PfEMP1 on the surface of infected erythrocytes by iodination and immunoprecipitation. Live 3D7k⁺, EMPΔ3, EMPΔ2, EMPΔ1 and the knockout parasite lines were surface labelled with ¹²⁵I, SDS extracts made and labelled PfEMP1 immunoprecipitated with anti-ATS antisera. Before solubilization, the intact labelled cells were treated with either trypsin plus STI (T+STI) or trypsin alone (T) as described previously (Baruch et al., 1996).