Employing a simple method of growing ookinetes of Plasmodium falciparum in culture, 40% of mature gametocytes convert to macrogametes, 4% reach the retort-form ookinete stage and 0.45% become mature ookinetes. A single-step gradient centrifugation method on 12.5% Nycodenz enriches both gametocytes and ookinetes.