The Use of an Immunoadsorbent in the Isolation of Australia Antigen

Australia antigen (Au‐ag) was isolated in a four‐stage procedure: pepsin hydrolysis, ultracentrifugation, gel filtration and immunoadsorption. The first three steps serve to remove serum proteins while leaving Au‐ag intact. In the immunoadsorption the remaining contaminant serum proteins are precipitated. A solid phase double antibody system was chosen. The effectiveness of the method was checked in various ways: double immunodiffusion, the production of a hyperimmune serum, gel filtration and immunofluorescence. Morphological integrity was checked by electron microscopy in every stage of the isolation.