Purification of early gametocyte stages from cultures of 3D7a parasites.

<p>The top panel shows stage I gametocytes stained with ethidium bromide (blue) and the sexual parasite-specific anti-Pfs16 antibody (green). The majority of nucleated erythrocytes are also Pfs16 positive and therefore gametocytes. The lower panel shows a Giemsa–stained thin film of the same culture 2 days later, when all parasites have reached Stage IIb of gametocyte development. Asexual parasite contamination was estimated at less than 1%.