A novel hepatitis B virus surface antigen immunoassay as sensitive as hepatitis B virus nucleic acid testing in detecting early infection.

Background: The aim was to considerably enhance the sensitivity of hepatitis B virus (HBV) surface antigen (HBsAg) detection and investigate whether the window period for HBV detection could be reduced.

Study Design And Methods: A high-sensitivity chemiluminescent enzyme immunoassay (CLEIA) was developed for quantitative HBsAg detection by a combination of monoclonal antibodies, each one for a specific epitope of HBsAg, and by improving the conjugation technique. The sensitivity of the assay was compared with that of the existing chemiluminescent immunoassay (CLIA).

The linker histone homolog Hho1p from Saccharomyces cerevisiae represents a winged helix-turn-helix fold as determined by NMR spectroscopy.

Hho1p is assumed to serve as a linker histone in Saccharomyces cerevisiae and, notably, it possesses two putative globular domains, designated HD1 (residues 41-118) and HD2 (residues 171-252), that are homologous to histone H5 from chicken erythrocytes. We have determined the three-dimensional structure of globular domain HD1 with high precision by heteronuclear magnetic resonance spectroscopy. The structure had a winged helix-turn-helix motif composed of an alphabetaalphaalphabetabeta fold and closely resembled the structure of the globular domain of histone H5.