| 摘要 |
NEW MATERIAL:A plasmid pNI20 having about 2.9Kb molecular weight, having enzyme-cut map expressed by the formula, causing no cleavage by restriction enzymes BamHI, Sacl, ClaI and SalI and derived from the genus Pseudomonas. USE:A vector for gene recombinant. PREPARATION:For example, Pseudomonas flavide IF-4 (FERM P-10865) strain is inoculated into a culture medium and cultured and then the cultured liquid is cooled and centrifuged to collect the bacteria and the bacteria are suspended to buffer liquid and lysozyme, pronase and RNAase are added thereto and are reacted therewith under cooling and the reaction product is cooled and centrifuged and the supernatant is separated and isopropanol is added to the resultant supernatant and precipitated DNA is separated and ethidium bromide and cesium chloride are added to the DNA and the DNA is subjected to supercentrifugal separation to separate plasmid DNA and part having same moving degree as straight-chain DNA of 1.6Kb is dissolved by electrophoresis and subjected to filter treatment to provide the pNI20 plasmid. |
