Vectors are DNA molecules that can carry foreign DNA into another cell and also replicate it. Also known as vehicle DNA.
Essential features of a cloning vector:
- Origin of replication: ORI is a specific sequence on a DNA molecule from where replication starts. It will also replicate the foreign DNA linked to it. It also controls the copy number of the linked DNA.
- Selectable markers: these are genes present in the vector that help us in identifying and eliminating non-recombinants (non-transformants) from recombinants (transformants). E.g., Antibiotic resistance genes such as tetracycline, ampicillin, chloramphenicol or kanamycin etc., in E.coli.
- Cloning sites/ recognition sites: it is site of a restriction endonuclease that is present only once in the cloning vector