An Improved Procedure for the Purification of Trypanosoma cruzi (Chagas, 1909) Metacyclics from the Insect Vector1

ABSTRACT. We have developed an improved procedure for isolating and purifying the metacyclic trypomastigote form of Trypanosoma cruzi from infected Triatoma infestans. The procedure was simple, did not require time-consuming removal of the insect gut, and gave a good recovery of metacyclics. Purification involved centrifugal flotation of the parasites in Percoll followed by diethylaminoethyl cellulose column chromatography. The resulting purified metacyclics exhibited no loss of infectivity when assayed in mice as compared to metacyclics taken directly from the insects.     

Tyrosine Aminotransferase Induction Regulation Variant in Tissue Culture

A variant of hepatoma tissue culture cells, described here, has normal basal levels of enzyme but fails to respond to the usual inducing steroids.