| 摘要 |
PURPOSE:To do precise replication in the host cells by preparing plasmid pNB-701 which has about 10.2 kilobase molecular weight and a specific incision point of the restriction enzyme as shown in the restriction map. CONSTITUTION:A strain in Streptomyces violaceoniger, bearing p-NB-701, such as KSA-6233 strain is cultured. Then, the cell bodies are collected, subjected to lysis with a lysin and then RNA, protein and other contaminants are removed from the solution. The product is subjected to density gradient ultra- centrifugation of electrophoresis-agarose gel column cutting to isolate the objective pNB-701. The plasmid is multicopying and a useful vector in cloning of the objective DNA. |
