Use of recombinant DNA technology for the production of polypeptides

DNA sequences corresponding to specific genes may be prepared by chemical synthesis, isolation of naturally occurring DNA, or reverse transcription. Such DNA may then be inserted into vectors such as plasmids or bacteriophages which carry the DNA into bacterial cells. Although significant differences exist in the basic molecular biology of eucaryotic and procaryotic organisms, these differences do not constitute absolute barriers to the expression of eucaryotic genes in bacteria. Several eucaryotic proteins, including insulin, growth hormone, ovalbumin, dihydrofolate reductase and somatostatin have been produced in bacteria. The use of chimeric microorganisms harboring recombinant DNA offers a completely new approach to the production of biologically useful polypeptides.