中文摘要：

以细胞总基因组提取试剂盒抽提PCV2细胞毒株总DNA为模板，用特异性引物扩增PCV2ORF3基因。将ORF3和表达载体pGEX-6p-1用BamltI和SalI双酶切回收后连接，将测序验证为阳性的重组质粒命名为pGEX-6p-1-ORF3。重组质粒pGEX-6p-1-ORF3转化BL21（DE3）后用IPTG诱导表达并纯化，对获得的表达产物进行SDS-PAGE电泳、Westernblot检测。结果表明：PCV2ORF3在pGEX-6p-1中获得了高效表达，其表达蛋白主要以包涵体形式存在，其分子质量约为37kD，且能够和PCV2阳性血清发生特异性相互作用，具有免疫学活性。

英文摘要：

Total DNA of porcine circovirus type 2 （PCV2） was extracted by the total cellular genome extraction kit, and a special primer was designed to amplify PCV20RF3 gene. Then, ORF3 and expression vector pGEX-6p-1 were digested by BarnH I and Sal I, and then were ligated together. The recombinant plasmid which sequencing test was positive was named as pGEX-6p-I-ORF3, and it was transformed into BL21 （DE3）, then the fusion proteins were expressed when it was induced by 1 mmol/ L of IPTG and purified. The obtained expression products were tested by SDS-PAGE and Western blot. The results showed that the PCV20RF3 was expressed in pGEX-6p-1, which mainly existed with the form of inclusion body; the ORF3 protein was 37 kD in molecular mass and it can generate specificity interaction with the positive serum of PCV2. Therefore, the ORF3 protein have a good immunology activity.