Genetic engineers can transfer a specific piece of DNA or genes from one organism to another organism. This is usually done by adapting recombinant DNA methods. In this approach, a gene of interest is cut with restriction enzymes and then inserted and ligated to the host genetic material. This host could be a bacteria or eukaryote.
Example: Biotechnologists can produce insulin by inserting human gene in <em>E. coli</em>. The bacteria replicate its genome fast and produce protein (insulin) which can be extracted and applied to the person who is diabetic. Similar methods have been used for other purposes.
