RESUMO
An expression genomic library of Trypanosoma cruzi was built by using plasmid pc DNA3 as a vector. This library served to immunize by intramuscular administration BALB/c inbred mice. A positive control group to which T. cruzi soluble antigens were administered and other group which was given the same plasmid used for the building of the genomic library were included in this study; another group was not immunized. Blood was extracted from the retrorbital plexus of all the mice two weeks after the third vaccination so as to study the specific antibody response to soluble parasite anigens through the Western Blot technique. The antibody response was shown in animals immunized with the expression genomic library and with soluble parasite antigens.