Simplified radioimmunoassay for viral antigens: use of Staphylococcus aureus as an adsorbent for antigen-antibody complexes.

In a rapid method for the radioimmunoassay (RIA) of viral antigens, Staphylococcus aureus was used as the adsorbent for antigen-antibody complexes ("protein A" molecules on the cell walls of certain strains of staphylococci have a strong affinity toward IgG molecules). The results showed that this method could be used instead of the double-antibody technique, with the same or probably higher sensitivity in precipitation as well as competition RIA's.