Haemagglutination assay for HBsAg -- a new approach to reagent preparation.

Human group O rhesus negative erythrocytes were spherocyted and fixed in glutaraldehyde, then coated initially with HBsAg and subsequently with anti-HBs. The resulting reagent was found to agglutinate in the presence of HBsAg positive serum, but not in HBsAg negative serum. The assay was evaluated for blood donor screening (39,962 donations) over a 6-month period, and was compared with Hepatest (RPHA) and AUSRIA-2 (RIA) for the study of two established HBsAg panels.