There are a broad range of various process for cloning DNA into either viral or plasmid vectors but the basic scheme of events is frequently same. To clone into a plasmid vector the round plasmid DNA is cut with a restriction enzyme which has only a one recognition site in the plasmid. This established a linear plasmid molecule with cohesive stops. The simplest cloning strategy is now to cut the foreign donor DNA with the same restriction enzyme. In the other words, different restriction enzymes can be used, giving that they create the similar cohesive ends. The donor DNA and linear plasmid DNA are now mixed. The cohesive stops of the foreign DNA anneal with the finishs of the plasmid DNA and are joined covalently by DNA ligase.