DNA cloning can either be based on cells or achieved by using polymerase chain

When two or more genes that have different kinds of gene code are combined they form Chimeric or fusion proteins. These genes are coded for separate proteins. Eventually a new polypeptide is formed with the functional properties of the proteins that were combined (Tierney, 2007).

DNA cloning can either be based on cells or achieved by using polymerase chain reaction(PCR).In the approach based on cells both the replicating molecule or the biological vehicle known as the vector and the foreign DNA fragment are cut using the same restriction enzyme(s ) to produce compatible cohesive (“sticky”) or blunt ends on the DNA molecules, then the foreign DNA fragment is permanently joined to the DNA of the vector using an enzyme known as DNA ligase which catalyzes the formation of a phosphodiester bond between the two DNA chains thus producing a chimera or a recombinant DNA molecule (Rychlik, 1990). The replicating molecule is meant to carry the foreign DNA fragment into the host cell (Chou & Bloch, 1992).