重组DNA

Recombinant DNA is DNA from different sources usually different species combined together in the laboratory for wide-spread uses in clinical and scientific research.

Recombinant DNA usually consists of a gene of interest, here insulin from a donor organism inserted into a vector, self-replicating DNA from another organism, such as a virus or a plasmid, a small circular piece of bacterial DNA. The DNA from each source is first cut by restriction endonucleases, enzymes that cleave DNA at a particular sequence.

The donor DNA is joined to the ends of the vector DNA with the help of the enzyme DNA ligase.

The recombinant DNA is then inserted into a host organism, a bacterium or yeast, where it's replicated, creating many copies of the gene of interest. The gene can then be more easily studied or, as in the case with insulin, translated into protein using the host's cellular machinery.