[Gene optimization, protein expression, purification and characterization of the HDV antigen for diagnosis].

Objective To prepare HDAg with biological activities as a candidate of diagnostic reagent.Methods To synthesize HDV gene fragment after codon optimization.To construct a thio-fused recombinant plasmid based on M48 expression vector.To express in E.coli induced by IPTG.To purify the protein by affinity chromatography followed by characterization in ELISA.Results Plasmid construction was verified by enzyme digestion.SDS-PAGE indicated the molecular weight of the protein was the same as we expectation.ELISA proved its affinity with HDV antibodies.Conclusion HDAg was obtained successfully and it will pave the road to the research of HDV diagnostic reagent. Key words: Genes; Thioredoxim; Chromatography; Hepatitis D