In attempts to develop a specifically reactive complement fixing antigen, desiccated Trypanosoma cruzi rendered essentially lipid-free by extraction with anhydrous ether were extracted in buffered saline solution and the saline extract treated with chloroform and n-amyl alcohol under conditions considered to minimize deterioration. This yielded protein and carbohydrate antigens separable, respectively, in the gel and aqueous phase of extracts thus treated. Each showed a high degree of specific reactivity, as demonstrated in complement fixation tests of sera representing the homologous and several heterologous infections. The findings indicated that the protein fraction was the antigen of choice for diagnostic complement fixation tests.
Present address: Division of Laboratories and Research, New York State Health Department, Albany 1.