a novel method of purification of specific hydatid cyst antigen

hydatid cyst fluid has been used as a source of antigen for the serodiagnosis of echinococcus granulosus infection. due to cross-reactions with antigens shared by other helminthes, the specific antigen from hydatid cyst fluid was purified by many workers. we used a relatively simple technique for purification of specific antigen from sheep hydatid cyst fluid. isopycnic ultracentrifugation with 30% ker was used followed by sds-page to check the purity of the antigen. the antigen was of 48 kda and used in elisa and ira with high sensitivity and specificity.