Antigenic differences among isolates of Plasmodium falciparum demonstrated by monoclonal antibodies

Hybridomas raised against two Papua New Guinea (PNG) isolates of Plasmodium falciparum secreted monoclonal antibodies which bound to schizonts of all seven PNG isolates tested but not to schizonts of four non-PNG isolates from Thailand, Nigeria, Ghana, and The Netherlands. Some of the monoclonal antibodies were tested for their ability to inhibit the growth of one PNG isolate, one Thai isolate, and one Nigerian isolate in vitro. Only the growth of the PNG isolate was inhibited, thus demonstrating functional antigenic differences among isolates of P. falciparum.