The principles involved in the use of both vector types are conceptually similar. The circular form is cleaved with a restriction nuclease giving a linear vector with cohesive ends. The insert DNA, cleaved by the same or compatible restriction enzyme, is incubated with the restricted vector, causing the two fragments to anneal. Covalent sealing utilizes DNA ligase, which to the 3' hydroxyl of the adjacent nucleotide on the other fragment.
Plasmid vectors
Plasmid vectors possess an origin of replication, ori, (a site where DNA replication initiates), a gene for antibiotic resistance, such as AmpR, which allows for selection of all cell clones carrying the plasmid, and a polylinker region which contains a variety of restriction sites from which to choose. The polylinker region is often located within the lacZ' gene, facilitating blue/white selection of bacterial colonies (the insert disrupts lacZ' transcription preventing a-complementation).
Phage vectors
Phage vectors (eg. lgt10) also possess a unique cloning site; in addition they possess complementary, cohesive (cos) ends - which may be regarded as giant sticky ends, operating on the same principle as the overlapping ends within overhanging restriction sites, but are much larger.
