[Sensitivity and various radioimmunologic procedures for the research and typization of the antigen and antibody of hepatitis B].

The kinetics of solid-phase radioimmunoassay (SPRIA) procedures for HBsAg detection were explored. Most HBsAg-positive sera showed an evident prozone phenomenon and the optimal reaction zone occurred at considerable dilution rates. Subsequent dilutions (in negative serum) resulted in a linear decrease of counts, plotted on log-logit graphs, to the lowest level of positivity (cpm positive serum/cpm negative sera=2.1/1). As compared with commercial solid-phase substrates, the sensitivity of HBsAg detection was enhanced when the SPRIA procedure was carried out in small polystyrene tubes, previously coated with purified antibody by simple contact. Various SPRIA procedures were described for HBsAg typing and suggested also as confirmatory tests for suspect positive sera. The sensitivity and the kinetics of three methods for the detection of anti-HBsAg antibody (anti-HBs) were investigated. These methods are based upon the neutralization of a standard dose of HBsAg (methods A and B) or upon the competitive inhibition of labeled antibody (method C). One of these methods fits the combined detection of HBsAg and anti-HBs. Finally, some SPRIA procedures were suggested for anti-HBs typing and some applications were shown.