The separation and structure of infective trypanosomes from cultures of Trypanosomas brucei grown in association with tsetse fly salivary glands.

Infective trypanosomes developed when Trypanosoma brucei was cultivated at 28 C in a liquid medium containing tsetse fly head-salivary gland explants. They were separated from the noninfective culture forms using DEAE-cellulose column chromatography. It was demonstrated by light and electron microscopy that the separated organisms were morphologically similar to metacyclic stages found in a tsetse fly and that they had a characteristic surface coat. Single metacyclic trypanosomes isolated from the cultures gave rise to infections in mice.