The Separation and Structure of Infective Trypanosomes From Cultures of Trypanosoma Brucei Grown In Association With Tsetse Fly Salivary Glands*

Abstract
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 chromatog‐raphy. 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.