Vectors for moleculars cloning

p align="left">The segments of foreign DNA cloned in these vectors can be propagated as plasmids. When cells harboring these plasmids are infected with a suitable helper bacteriophage, the mode of replication of the plasmid changes under the influence of the gene II product of the incoming virus.

Interaction of the intergenic region of the plasmid with the gene II protein initiates the rolling-circle replication to generate copies of one st