RESUMO
Trypanosoma cruzi, is a protozoan parasite, which has a close phylogenetic relationship with Trypanosoma rangeli that is not pathogenic for the vertebrate host. Both parasites have antigenic similarity, they have different and complex total protein profiles according to their morphological and physiological stage epimastigotes or trypomastigotes, showing a differential gene expression during the life cycle. There are also differences according to T. cruzi populations used, which were isolated from different geographical areas and were harvested from different sources. This study clearly showed the Colombian SA strain that is highly virulent, has differences in its protein profile when as compared with Dm28c clone, Tulahuen strain and Colombian Astec strain which is not virulent. The proteins were separated by polyacrylamide gel electrophoresis (SDS-PAGE). Specie-specific proteins were found which allow us to identify them, just as it occurs with T. rangeli (Choachí-2V strain), which has three protein bands. However, two of them are not only present in epimastigotes but also in trypomastigotes, but the other is exclusive of epimastigote forms.