The techniques of genetic engineering have been used to manipulate the DNA (genetic material; see nucleic acid ) of bacteria and other organisms to manufacture biological products such as drugs (insulin, interferon, and growth hormones). A common technique involved in this process in gene splicing, in which a gene that produces a desired product can be inserted into bacterial DNA. Bacteria can then be grown in large quantities and processed to extract the desired substance; specially cultured plant and animal cells can be similarly grown and processed. Hybrids of cancer and antibody-producing cells (hybridomas) have been cloned in the laboratory to mass produce experimental monoclonal antibodies , which are being studied for the treatment of cancer and other diseases. Bacteria have also been altered to break down oil slicks and industrial waste products.
Plants and foods with such desired qualities as prolonged shelf life or increased resistance to diseases and pests have been created through genetic engineering; that is, by inserting DNA from other organisms. Much of the corn and soybeans grown in the United States, for example, are now genetically modified in some way, Livestock have also been genetically altered to produce medically useful substances (see pharming ). The field of biotechnology also includes gene therapy , in which attempts are made to insert normal or genetically altered genes into cells to treat genetic disorders and chronic diseases.
See R. W. Old and S. B. Primrose, Principles of Gene Manipulation (5th ed. 1994); J. E. Smith, Biotechnology (3d ed. 1996).
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.
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