Abstract
An adaptation of the immunoblotting technique was used to investigate binding interactions between Trypanosoma cruzi and mammalian host cells at the molecular level. A specific binding interaction was observed between T. cruzi and two host cell membrane polypeptides with molecular masses of approximately 32 and 34 kilodaltons. This molecular interaction was observed with antigen extracts of T. cruzi and with live, infective trypomastigote stages of the parasite, suggesting that the observed phenomenon may have relevance to the initial attachment of the parasite to the host cell membrane before invasion.