Recombinant DNA

Deoxyribonucleic acid (DNA) is the information blueprint that exists in most living organisms. Some viruses instead contain ribonucleic acid (RNA). Even these viruses require the production of DNA at some stage of their replication.
DNA from different organisms of the same species combines together naturally to yield an organism that has traits from both parent organisms. There is also evidence accumulating that DNA transfer between different species may be a natural process. However, much interspecies mixing of DNA is the result of deliberate experimental manipulations.
A crucial process of these manipulations is the preparation of recombinant DNA. Recombinant DNA is DNA from different organisms that have been chemically bonded together to form a single DNA. The recombinant DNA can be interpreted by the various enzymes of prokaryotic or eukaryotic cells, so that the genes contained in the recombinant DNA can be expressed and the protein products produced.
The recombination can involve the DNA from two eukaryotic organisms, two prokaryotic organisms, or between an eukaryote and a prokaryote. An example of the latter is the production of human insulin by the bacterium E .COLI, which has been achieved by splicing the gene for insulin into the E. coli genome such that the insulin gene is expressed and the protein product formed.