A microtiter solid-phase radioimmunoassay for hepatitis A antigen and antibody.

A microtiter solid phase radioimmunoassy for hepatitis A antigen (HA Ag) and antibody (anti-HA) was developed. The test was more sensitive than immune adherence hemagglutination for detecting HA Ag and almost as sensitive for detecting anti-HA. The specificity and sensitivity of reagents were examined and optimum conditions for the test were determined. Radioimmunoassay, immune adherence hemagglutination, and immune electron microscopy were compared for detecting anti-HA. A serologic response to HA Ag was detected in paired sera from patients with type A hepatitis but not from patients with type B or non-A, non-B hepatitis by all three techniques.