Immune precipitation and immunoblotting for the detection of Trypanosoma cruzi antigens.

The efficiency of immunoprecipitation and immunoblotting for detecting Trypanosoma cruzi antigens using rabbit and mouse antisera has been examined. Comparison of the starting material for each technique showed that the extraction methods resulted in a similar range of polypeptides when assessed by apparent Mr. Reaction with either hyperimmune rabbit sera or a sequential series of sera from infected mice, showed a significant disparity in the range of antigens revealed by each technique. Epitopes on polypeptides greater than 50 kDa were poorly preserved by immunoblotting compared to immunoprecipitation; however, below this threshold both techniques were equally efficient. Under the conditions of assay, it is probable that immunoprecipitation allows effective detection of both sequence and conformational determinants, whereas immunoblotting favours the detection of sequence determinants alone.