Radioimmunoassay detection of HBsAg in hemoderivatives

The aim of the present paper is that of developing a technique which exploiting a commercial RIA Kit (Ausria II - Abbott) could be employed for the detection of HBsAg also in products different from serum or plasma, such as hemoderivates, even when as negative control is employed the kit, made up of a pool of HBsAg and HBsAb negative plasma. In order to lower the probability of false positive and false negatives the Authors employed, in parallel with the normal Abbott technique, a modified technique, which involves the presaturation of the polystyrene beads with human serum albumin solution. This technique showed to increase the sensitivity relevant to the kit itself. The technique with successive contacts employed by the Authors allowed the carrying out of the confirmation test for those blood derivatives also, which tend to clot, both due to the treatments and for the addition of the reagents employed in the confirmation test. In order the get a better garantee in classifying as "non-reactive" a sample the Authors expect it to be timely to carry out, in addition to the direct test, a confirmation test. Samples with titrated HBsAg additions and showing C/N > 1.5 in the direct test, turned out reactive to the confirmation test. Recovery tests show, even considering the variability of the sensitivity of the kit, according to the batch and the date of use, an indication of the sensitivity of the RIA method for HBsAg detection in hemoderivatives.