Surface proteins in different isolates of Trypanosoma cruzi epimastigotes.

Epimastigotes from several Trypanosoma cruzi stocks were labeled by iodination with Chloramine T and their proteins detected by gel electrophoresis and autoradiography. The labeled proteins from the parasite surface were detected after immunoprecipitation with antisera against fixed trypanosomes or from infected rabbits. These antisera were able to recognize one or more proteins in all T. cruzi isolates analyzed, but the individual patterns differed from each other. Variations in the surface protein patterns were also observed in two Tulahuen stocks kept during several years under different conditions. Growth medium as well as the stage of growth at which the parasites were collected had also an effect upon the relative amount of the observed labeled proteins.