6 • Impacts of Applied Genetics— Micro-Organisms, Plants, and Animals 
Figure 2.— The Product Development Process 
Micro-organisms such as E. coli 
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The development process begins by obtaining DNA either through organic synthesis (1) or derived from biological sources such as tissues 
(2). The DNA obtained from one or both sources is tailored to form the basic “gene" (3) which contains the genetic Information to "code" tor a 
desired product, such as human interferon or human insulin. Control signals (4) containing instructions are added to this gene (5). Circular DNA 
molecules called plasmids (6) are isolated from micro-organisms such as E. coli-, cut open (7) and spliced back (8) together with genes and con- 
trol signals to form “recombinant DNA” molecules. These molecules are then introduced into a host ceii (9). 
Each piasmid is copied many times in a cell (10). Each cell then translates the information contained in these plasmids Into the desired prod- 
uct, a process calied “expression” (11). Cells divide (12) and pass on to their offspring the same genetic information contained in the parent 
cell. 
Fermentation of large populations of geneticaliy engineered micro-organisms is first done in shaker fiasks (13), and then in small fermenters 
(14) to determine growth conditions, and eventually in larger fermentation tanks (15). Cellular extract obtained from the fermentation process la 
then separated, purified (16), and packaged (17) either for industrial use (18) or health care applications. 
Health care products are first tested in animal studies (19) to demonstrate a product’s pharmacological activity and safety. In the United 
States, an investigational new drug application (20) is submitted to begin human clinical trials to establish safety and efficacy Following 
clinical testing (21), a new drug application (NDA) (22) is filed with the Food and Drug Administration (FDA). Vi/hen the NDA has been reviewed 
and approved by the FDA the product may be marketed in the United States (23). 
SOURCE: Genentech, Inc, 
