ABSTRACT
<p><b>OBJECTIVE</b>To obtain high yield and good antigenic activity of HDV L-Ag and to detect different regional patients' sera to test the purified antigen's antigenicity.</p><p><b>METHODS</b>Hepatitis delta virus' sequence was obtained from Inner Mongolian patient by using RT-PCR and PCR methods, PET43a was used and His-tag was added at the HDV L-Ag 5' and 3' to construct the recombinant expression plasmid, transform the plasmid into host bacterium BL21 and induce it with IPTG. The expression supernatant was purified by saturated (NH4)2SO4 and affinity chromatography. The activity and antigenicity of the expressed product were analyzed by using EIA.</p><p><b>RESULTS</b>Comparison of results obtained with detection by using the expressed protein coated plate and ABBOTT Murex anti-Delta (total) of 15 positive and 10 negative sera, the consistency was good (100%).</p><p><b>CONCLUSION</b>EIA proved that the purified antigen had good antigenicity, no serological difference was found in detection between different region's sera, therefore the purified delta antigen may be useful in diagnostic and other research.</p>