乙型肝炎病毒核心抗原(HBcAg)的基因片段为 lkb。用 Bgl Ⅱ酶解 pSH117,回收lkb 片段;用 BamHI 酶解 pUR222,回收片段。将得到的 DNA 片段分别用 CIP 处理。然后用T_4DNA 连接酶连接,转化到 EcoIiBMH71-18中表达。经过筛选和检测,得到了3株高效表达的 HBcAg 阳性克隆菌株,再经 ELISA 检测,其效价可达1024x。酶解和分析电泳,重组质粒小于3.7kb。 Hepatitis B virus core antigen (HBcAg) gene fragment is lkb. The pSH117 was digested with Bgl II, the lkb fragment was recovered, and the pUR222 was digested with BamHI to recover the fragment. The resulting DNA fragments were treated with CIP, respectively. Then ligated with T_4 DNA ligase and transformed into EcoIiBMH71-18 for expression. After screening and testing, three highly expressed HBcAg positive clones were obtained, and their titres were up to 1024x by ELISA. Enzymatic hydrolysis and analysis, the recombinant plasmid is less than 3.7kb.