Recombinant DNA is used for genetics research, cloning, creating genetically modified organisms and producing biomedical products. The production of insulin for human consumption inserts recombinant DNA into bacteria or yeast in order to make insulin. This allows the production of human insulin rather than harvesting insulin from cows or pigs.
Recombinant DNA refers to any DNA that has been created artificially from two or more sources. One method of using recombinant DNA to produce gene products such as insulin is to make plasmids. Plasmids are small circular pieces of DNA that can be inserted into bacteria without insertion into the regular DNA chromosome. Plasmids often have locations that can be cut so that a gene of interest can be inserted. For example, the creation of insulin requires a plasmid that has had the human insulin gene inserted. This process makes insulin using recombinant DNA much safer for people with allergies to pig or cow products, which are the typical sources for insulin.
When recombinant DNA is used to make genetically modified organisms for food use, the desired gene is inserted into a plasmid. That plasmid is then inserted into bacteria to produce the gene or protein of interest, and this gene is inserted into the plants.
Recombinant DNA and cloning are also used in research to add genes of interest to model organisms so that the result can be studied.