The pJET1.2/blunt cloning vector carries a lethal restriction enzyme gene that is disrupted by ligation of a DNA insert into the cloning site. As a result, only bacterial cells with recombinant plasmids are able to form colonies. If the pJET1.2/blunt vector re-circularizes without an insert, it expresses the lethal restriction enzyme which kills the host E. coli cell after transformation. This positive selection drastically accelerates the process of colony screening and eliminates additional costs required for blue/white selection.
For convenience in mapping and manipulation of the insert, the pJET 1.2/blunt vector multiple cloning site contains two BgIII recognition sequences that flank the insertion site. In addition, the vector contains a T7 promoter for in vitro and in vivo transcription as well as sequencing of the insert.