Ch. 1 Summary: Issues and Options • 5 
Figure 1.— Recombinant DNA: The Technique of Recombining Genes 
From One Species With Those From Another 
Electron micrograph of the DNA, which is the plasmid SP01 
from Bacillus subtilis. This plasmid which has been 
sliced open is used for recombinant DNA research 
in this bacterial host 
amount of DNA protein 
SOURCE: Office of Technology Assessment. 
For some pharmaceutical products, biotech- 
nology will compete with chemical synthesis 
and extraction from human and animal organs. 
Assessing the relative worth of each method 
must be done on a case-by-case basis. But for 
other products, genetic engineering offers the 
only method known that can ensure a plentiful 
supply; in some instances, it has no competition. 
By making a pharmaceutical available, genet- 
ic engineering may have two types of effects: 
• Drugs that already have medical promise 
Photo credits: Professor F. A. Eiserling, UCLA Molecular Biology Institute 
Electron micrograph of Bacillus subtilis in the process of 
cell division. The twisted mass in the center of each 
daughter cell is the genetic material, DNA 
Restriction enzymes recognize certain sites along the DNA 
and can chemically cut the DNA at those sites. This makes 
it possible to remove selected genes from donor DNA mole- 
cules and insert them into plasmid DNA molecules to form 
the recombinant DNA. This recombinant DNA can then be 
cloned in its bacterial host and large amounts of a desired 
protein can be produced. 
will be available in ample amounts for clin- 
ical testing. Interferon, for example, can be 
tested for its efficacy in cancer and viral 
therapy, and human growth hormone can 
be evaluated for its ability to heal wounds. 
• Other pharmacologically active substances 
for which no apparent use now exists will 
be available in sufficient quantities and at 
low enough cost to enable researchers to 
explore new uses. As a result, the potential 
for totally new therapies exists. Regulatory 
proteins, for example, which are an entire 
