How is recombinant DNA technology useful?

Through recombinant DNA techniques, bacteria have been created that are capable of synthesizing human insulin, human growth hormone, alpha interferon, hepatitis B vaccine, and other medically useful substances. Recombinant DNA technology also can be used for gene therapy, in which a normal gene is introduced into an individual’s genome in order to repair a mutation that causes a genetic disease. The ability to obtain specific DNA clones using recombinant DNA technology has also made it possible to add the DNA of one organism to the genome of another. The added gene is called a transgene, which can be passed to progeny as a new component of the genome. The resulting organism carrying the transgene is called a transgenic organism or a genetically modified organism (GMO). In this way a “designer organism” is made that contains some specific change required for an experiment in basic genetics or for improvement of some commercial strain.