1. Isolate The Insulin Gene
The gene for producing HUMAN insulin
protein is isolated. The gene is
part of the DNA in a human
chromosome. The gene can be isolated
and then copied so that many insulin
genes are available to work with
2. Prepare Target DNA
In 1973, two scientists named Boyer and Cohen developed a way to take
DNA from one organism and put it in the DNA of bacterium - using the
E.Coli bacteria as a FACTORY. This process
is called recombinant DNA technology. First, a circular piece of DNA
called a plasmid is removed from a bacterial cell. Special proteins are
used to cut the plasmid ring open.
3. Insert DNA into Plasmid
With the plasmid ring open, the gene for insulin is inserted into the
plasmid ring and the ring is closed - by another special enzyme-. The human insulin gene is now
recombined with the bacterial DNA plasmid.
4. Insert Plasmid back into cell
The bacterial DNA now contains the human insulin gene and is inserted
into a bacteria. Scientists use very small needle syringes to move the
recombined plasmid through the bacterial cell membrane.
5. Plasmid multiply
Many plasmids with the insulin gene are inserted into many bacterial
cells. The cells need nutrients in order to grow, divide, and live.
While they live, the bacterial cell processes turn on the gene for human
insulin and the insulin is produced in the cell. When the bacterial
cells reproduce by dividing, the human insulin gene is also reproduced
in the newly created cells.
6. Target Cells Reproduce
Human insulin protein molecules produced by bacteria are gathered and
purified. The process of purifying and producing cow and pig insulin has
been greatly reduced or eliminated.
7. Cells Produce Proteins
Millions of people with diabetes now take human insulin produced by
bacteria or yeast (biosynthetic insulin) that is genetically compatible
with their bodies, just like the perfect insulin produced naturally in