[Experiences with an enzyme-immunoassay for hepatitis B antigen detection in blood donors (author's transl)]

In a comparative study 12,080 sera from unpaid donors were tested simultaneously for Hepatitis B Antigen (HBsAg) by enzyme-immunoassay (EIA) and radioimmunoassay (RIA). A relatively high number of sera reacted positive in the EIA-secreening test but were negative after repeated investigation. This percentage could be markedly reduced when using an automated washing apparatus. After neutralization 0.31 per cent were considered as true positive in EIA and RIA, thus demonstrating that no differences did exist as far as sensitivity is concerned. The EIA needs more incubation time than the RIA, however, the EIA has the advantage of using enzyme-labelled antibodies instead of radio-iodinated reagents. The results are read immediately and no sophisticated equipment is required. The EIA is easy to handle, two technicians can perform 1000 tests per day.