The authors tested 366 samples for the detection of HBcAb using enzyme-linked immunosorbent assay (ELISA) and radioimmuno assay (RIA). Twenty samples were titered to compare the sensitivity of the two tests. The results showed that the two methods gave very similar results, with only a few doubtful cases for RIA. ELISA seems to be more sensitive than RIA for the titration of the positive samples. The authors conclude that the ELISA method is easier than RIA and does not require any apparatus in particular.