Partial purification of fasciola hepatica antigen for the immunodiagnosis of fascioliasis in rats.

When F. hepatica adult worm antigen is fractionated with Sephadex G-200, four major peaks are obtained. The first peak, when used as antigen in counterelectrophoresis, reacts with the serum of normal rats as well as from rats infected with F. hepatica for 5 weeks or longer. The crest and descending portion of peak II and the third peak are nonreactive with normal rat serum, but highly reactive with the serum of rats with F. hepatica. In addition, F. hepatica antigens cross-reacting with S. mansoni adult worm antisera are absent in these fractions. It is suggested, then, that these fractions of F. hepatica adult worm antigen be utilized for the immunodiagnosis of fascioliasis by CEP. Optimum antigen concentration for this test has been determined to be approximately 1.80 mg/ml protein.