Abstract: The level of specific immunoglobulin G (IgG) in sera of hydatidosis patients against Echinococcus granulosus antigen is detected in dot-immunobinding assay with purified and crude Echinococcus granulosus antigens.The experiment carried out with purified antigen and the serum 1∶200 obtains higher specificity (98.9%);meanwhile,the experiment maintains the higher sensitivity (93.7%) which is obtained in the experiment carried out with crude antigen and the serum dilution 1∶400.These results indicate that in the research of specific immunoglobulin G in sera of hydatidosis patients anti-Echinococcus granulosus antigen,higher sensitivity (93.7%) and higher specificity (98.4,98.9%) can be obtained with purified Echinococcus granulosus antigen and crude Echinococcus granulosus antigen respectively;higher specificity is achieved when purified antigen is used,but there is no significant difference between purified and crude antigen in statistics.

Key words: hydatidosis;echinococcus granulosus antigen;immunoglobulin G;immune , response;dot immunobinding assay