A simple two-step procedure was devised for the preparation of a fraction of sheep hydatid fluid containing two major lipoprotein antigens. The physicochemical characteristics of the antigens were examined by gel filtration, electrophoresis, immunoelectrophoresis, and chemical analysis. The degree of contamination by host serum proteins was measured with specific precipitation of 125I-labelled antigen and found to be in the region of 1.6%. One component of the fraction was further purified by gel filtration on Sephadex G-200 and its approximate molecular weight calculated to be 160,000.
Permanent address: Médicine Expèrimentale, Collège de France, Paris Ve, France.
Biochimie Generales, Collège de France, Paris Ve, France.