摘要
用内切酶SacⅠ和HindⅢ双酶切大肠杆菌质粒pEWD299,回收505bp的LTB基因片段,再将载体pUC18用SacⅠ和HindⅢ双酶切,最后将pUC18DNA与505bp的LTBDNA进行连接,转化至受体菌DH5α中,经SacⅠ/HindⅢ、EcoRⅠ/HindⅢ酶切反应鉴定重组子,得到了理想重组子质粒pXLT1。再将pXLT1进行EcoRⅠ酶切、大肠杆菌聚合酶ⅠKlenow大片段补平、HindⅢ酶切处理,然后与用HicⅡ和HindⅢ酶切的pUC18连接,转化至受体菌DH5α中,经XbaⅠ/HindⅢ酶切反应鉴定重组子,得到了理想重组子质粒pXLT1-1。将质粒pXLT1-1进行核苷酸序列分析。
We used the restriction endonucleases SacⅠ and HindⅢ to digest the plasmid pEWD299,isolated by 1.5% agarose gel electrophoresis,recovered the 505 bp LT B gene fragment,then we inserted it into the vector pUC18 which digested with SacⅠ and HindⅢ,by blunt end ligation.The ligation mixture was used to transform Escherichia coli DH5α.The transformants were screened on ampiciline/X Gal/IPTG plates.One recombinant plasmid,pXLT1-1,was identified with restriction endonucleases (SacⅠ,HindⅢ,SacⅠ/HindⅢ and EcoRⅠ/HindⅢ).The nucleotide sequence analysis reveals the DNA sequence of heat labile enterotoxin B subunit gene in Escherichia coli.
出处
《畜牧与兽医》
北大核心
1997年第4期154-156,共3页
Animal Husbandry & Veterinary Medicine