Printed in U.S.A. THE IMMUNOELECTROPHORETIC CHARACTERIZATION OF SHEEP HYDATID CYST FLUID ANTIGENS

Abstract. The antigens for the Echinococcus granulosus-specific arc S were found in 40 of the 42 hydatid cyst fluid (HCF) pools obtained from the lungs and liver of sheep by the immunoelectrophoresis (IEP) test using sheep and rabbit antisera to HCF. The criteria for the selection of antigens for the diagnosis of human hydatidosis by the IEP test are reviewed in the light of this finding. Sheep antisera to ovine HCF did not show antibody activity to the host contaminants in HCF. The value of such an antiserum for the isolation of the E. granulosus antigens in HCF, and in immunologic and phylogenetic studies of parasites and its application as a reference serum for the IEP test for human hydatid disease are discussed. Capron et al.'2 consider that a HCF lot should be selected for use in the IEP test if it contains a maximum of parasite antigens (including the arc S antigens) and a minimum of host con taminants. This criterion for antigen selection is also re-examined in the present study. MATERIALS AND METHOD