The gene for producing a protein is isolated from a cell.
The gene is on the DNA in a chromosome. Special DNA cutting
proteins are used to cut out certain sections of DNA. The
gene can be isolated and then copied so that many genes are
available to work with.
2. Prepare Target DNA
In 1973, two scientists named Boyer and Cohen developed a
way to put DNA from one organism into the DNA of bacteria.
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 to open it up.
3. Insert DNA into Plasmid
The host DNA that produces the wanted protein is inserted
into the opened plasmid DNA ring. Then special cell proteins
help close the plasmid ring.
4. Insert Plasmid back into cell
The circular plasmid DNA that now contains the host gene
is inserted back into a bacteria cell. The plasmid is a natural
part of the bacteria cell. The bacteria cell now has a gene
in it that is from a different organism, even from a human.
This is what is called recombinant DNA technology.
5. Plasmid multiplies
The plasmid that was inserted into the bacteria cell can
multiply to make several copies of the wanted gene. Now the
gene can be turned on in the cell to make proteins.
6. Target Cells Reproduce
Many recombined plasmids are inserted into many bacteria
cells. While they live, the bacteria's cell processes turn
on the inserted gene and the protein is produced in the cell.
When the bacterial cells reproduce by dividing, the inserted
gene is also reproduced in the newly created cells.
7. Cells Produce Proteins
The protein that is produced can be purified and used for
a medicine, industrial, agricultural, or other uses. Check
out the Uses section to see how GE is used.