RAPID-DETERMINATION OF HEPATITIS-B SURFACE-ANTIGEN (HBSAG) BY LATEX AGGLUTINATION USING AN INTEGRATING SPHERE TURBIDIMETRIC ASSAY

A method for determining levels of serum HBs antigen has been developed, applying the principles of the integrating sphere turbidimetric assay (ISTA). Using this method, the minimum detectable level of HBs antigen is 15 ng/ml, i.e., it is three times more sensitive than the reversed passive hemagglutination (RPHA) method. Reproducibility and specificity are also excellent with ISTA. With a cut-off level of 20 ng/ml, the highest reading possible with this method is 1000 ng/ml. Serum HBs antigen can readily be measured by this method if a fully automated EL-1000 analyzer is used. This rapid and simple method of measurement should be clinically useful.