a replicon used for the transformation of cells in gene manipulation. Small plasmids, viruses and bacteriophages are suitable, since they are replicons in their own right. They can be artificially constructed by cutting and joining DNA molecules from different sources using restriction enzymes and ligases.
If the vector is a virus, cosmid, or phasmid:
(i) it should have a restricted host range;
(ii) it should be rendered non-lysogenic when used as a cloning vector (e.g. defective in the CI- lambda repressor).
