the first researchers to develop a sandwich I-PCR assay for
the detection of viral antigens, including the hepatitis B
surface antigen (HBsAg) of hepatitis B virus (HBV), which
combined the specificity of two high-affinity anti-HBsAg
mAbs employed both as capture and as detection antibody
(Table 1). The use of two-site mAbs was found to greatly
enhance the specificity and sensitivity of the assay such that
it could detect as little as 0.5 pg HBsAg in serum samples