Detection of hepatitis B antigen in blood donors by radioimmunoassay and three reverse passive haemagglutination techniques.

In a comparative study 5,569 sera from voluntary donors were tested simultaneously for hepatitis B antigen by three reverse passive haemagglutination (RPHA) techniques (Auscell, Hepanosticon, Hepatest) and the radioimmunoassay (RIA) (Ausria II). Among the three RPHA methods, no significnat differences could be found as far as sensitivity is concerned. The percentage of positive sera detected by these RPHA methods varies from 0.43 to 0.56%. Eleven sera were detactable only by Ausria II. Except for two, all these sera had low counts per minute in the RIA.