Immunohistochemical detection of Trypanosoma cruzi in tissues of mice with experimental Chagas' disease.

We compared two immunoperoxidase procedures for the identification of Trypanosoma cruzi antigens in wax sections of infected mouse tissues. Both an indirect immunoperoxidase and an avidin-biotinated horseradish peroxidase complex (ABC) procedure gave identical patterns of localization. The ABC procedure could be used with greater dilutions of antisera than the indirect procedure. Individual organisms were clearly identified in the absence of inflammation at scanning magnifications. In addition, fragments of parasites were identified in inflammatory lesions. Therefore, this technique should be valuable in experimental and clinical situations when the identification of few organisms or fragments of organisms is required.