| 主权项 |
1. A plasmid comprising the following units:
(a) an endonuclease restriction site, (b) a promotorless endonuclease expression cassette, (c) a promoter, (d) a sequence coding for an enzyme that catalyzes site-specific recombination, (e) at least two recognition sequences for the enzyme catalyzing site-specific recombination, and (f) a sequence of interest and an element preventing the expression of the endonuclease which are both arranged between said recognition sequences for the enzyme catalyzing site-specific recombination, wherein the functional units are arranged on the plasmid such that the endonuclease expression cassette is placed under control of the promoter only after recombination at the specific recognition sequences. |
