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采用ＰＣＲ定点突变方法，成功地构建了抗ＨＢｓＡｇｄｓＦｖ抗体的轻、重链突变基因，ＮｄｅＩ和ＥｃｏＲＩ酶切后分别插入ｐＥＴ２０ｂ表达质粒，经测序证明在重链第４４位氨基酸和轻链第１００位氨基酸已突变形成半胱氨酸（Ｃｙｓ）。ＶＨ和ＶＬ重组质粒分别转化到大肠肝菌ＢＬ２１（ＤＥ３）中，ＩＰＴＧ诱导后，经ＳＤＳＰＡＧＥ电泳表明在１２ｋＤ处有包含体蛋白表达，表达蛋白含量分别为２８％和３５％。ＶＨ和ＶＬ包含体蛋白经ＧｕＨＣｌ变性后，等量混合在复性折叠液中结合，形成了一个约２４ｋＤ并有一定活性的ｄｓＦｖ蛋白。抗ＨＢｓＡｇｄｓＦｖ抗体表达及复性的成功，为今后基因工程抗体的研究及应用奠定了基础。
The light and heavy chain mutations gene of anti-HBsAgdsFv antibody was successfully constructed by PCR site-directed mutagenesis. After digested with NdeI and EcoRI, the recombinant plasmid pET20b was inserted into expression vector pET20b. Sequencing showed that the amino acid at the 44th and the 100th amino acid in the light chain Has been mutated to form cysteine (Cys). The recombinant plasmids of VH and VL were transformed into E. coli BL21 (DE3) respectively. After IPTG induction, SDS-PAGE analysis showed that the inclusion bodies expressed at 12kD and the expressed protein contents were 28% and 35% respectively. The VH and VL inclusion bodies were denatured by GuHCl and mixed in equal amounts to form a dsFv protein of about 24 kD with some activity. The successful anti-HBsAgdsFv antibody expression and refolding laid the foundation for the future research and application of genetically engineered antibodies.