An Indirect Fluorescent Antibody Technique Using Soluble Antigens for Serodiagnosis of Trypanosoma cruzi Infection

Abstract

Summary A soluble antigen fluorescent antibody (SAFA) technic for the serorecognition of American trypanosomiasis is described. The technic has the following advantages over the conventional whole organism indirect fluorescent antibody tests: 1) permits the investigator to objectively select the antigen; 2) provides for mechanical reading of test results; 3) eliminates the problem of fading; and 4) accounts for nonspecific fluorescence contributed by the patient's serum (e.g., drugs) and/or by free fluorescein in the conjugated antiserum. Preliminary investigations revealed that exo, somatic carbohydrate and somatic protein antigens from T. cruzi would adhere to the artificial matrix. The sensitivity and specificity of the somatic protein and exoantigens were evaluated, The findings indicate that the SAFA technic with either of these 2 antigens should yield excellent results.