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).

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).

Fusion proteins can occur naturally by a process known as chimeric mutation. This process occurs when there is a high level of mutation. This creates a new coding system from the two genes.

Fusion proteins can be created in two ways. There is the artificial way and this is known as Recombinant fusion. This kind of fusion is got from the process known as recombinant DNA technology. This technology is used for research in biological fields.