人乙型肝炎肝硬化组织cDNA文库的构建及鉴定

目的:构建人乙型肝炎肝硬化组织cDNA文库,为筛查与乙型肝炎肝硬化的发生特异相关的基因及探讨乙型肝炎肝硬化的发病机制奠定基础.方法:用Trizol方法提取人乙型肝炎肝硬化组织总RNA,并用mRNA纯化试剂盒进行mRNA纯化;反转录合成单链cDNA,长距离PCR方法合成双链cDNA;PCR产物经蛋白酶K水解、纯化后,用Sfi I酶切;将酶切产物进行分级分离,回收0.4 kb以上的cDNA组分,并与λTripl Ex2载体连接;连接产物经体外蛋白包装,产生未扩增文库;鉴定文库的滴度和重组效率后,进行文库扩增;鉴定扩增文库的滴度和重组效率;随机挑取11个噬菌斑,用载体克隆位点两端的通用引物进行PCR扩增,以检测所构建的cDNA文库的质量.结果:未扩增文库滴度为1.03×106 pfu/ml,重组效率为97.24%,扩增后文库滴度为1.36×109 pfu/ml,重组效率为99.02%;用载体两端的通用引物进行PCR鉴定,插入片段平均长度为1.02 kb,含1 kb以上的占36.36%,0.5～1 kb的占63.64%.结论:已成功构建一高质量的人乙型肝炎肝硬化组织cDNA文库,为筛查与乙型肝炎肝硬化的发生特异相关的基因及探讨乙型肝炎肝硬化的发病机制奠定了基础.

Construction and characterization of a cDNA library from human liver tissue of cirrhosis

OBJECTIVE: To construct a cDNA library from human liver tissue of cirrhosis. METHODS: The total RNA from human liver tissue of cirrhosis was extracted using Trizol method, and the mRNA was purified using mRNA purification kit. SMART technique and CDSIII/3' primer were used for first-strand cDNA synthesis. Long distance PCR was then used to synthesize the double-strand cDNA that was then digested by proteinase K and Sfi I, and was fractionated by CHOMA SPIN-400 column. The cDNA fragments longer than 0.4 kb were collected and ligated to lambdaTripl Ex2 vector. Then lambda-phage packaging reaction and library amplification were performed. The qualities of both unamplified and amplified cDNA libraries was strictly checked by conventional titer determination. Eleven plaques were randomly picked and tested using PCR with universal primers derived from the sequence flanking the vector. RESULTS: The titers of unamplifed and amplified libraries were 1.03 x 10(6) pfu/ml and 1.36 x 10(9) pfu/ml respectively. The percentages of recombinants from both libraries were 97.24 % in unamplified library and 99.02 % in amplified library. The lengths of the inserts were 1.02 kb in average (36.36 % 1 approximately equals 2 kb and 63.64 % 0.5 approximately equals 1.0 kb). CONCLUSION: A high quality cDNA library from human liver tissue of cirrhosis was constructed successfully, which can be used for screening and cloning new special genes associated with the occurrence of cirrhosis.