Making human insulin from bacteria

igocheddarBiotechnology

Dec 14, 2012 (4 years and 7 months ago)

173 views

Genetic Engineering

Some diabetics need to inject insulin. We used to get

insulin from cows or pigs, but that took time and

money. We now use bacteria to produce insulin

because they can make it quickly and cheaply.



How can bacteria be used to produce insulin?


We need to isolate the DNA sequence bases for human
insulin and put it into bacteria.



How could we isolate and cut out a desired gene from DNA?







Making human
insulin from bacteria:


1.
Use a restriction enzyme
to cut out the gene. The
enzyme acts as a genetic
scissors which cuts DNA at
to specific sequence of
nucleotides
. Sticky ends
are left over with
nonpaired bases.


Sticky ends can form hydrogen

bonds with complementary sticky

end base pairs on any other DNA

molecule cut with the same

enzyme

Making human
insulin from bacteria:


2.
Separate insulin from the
rest of the DNA by gel
electrophoresis.


2.
Use Polymerization Chain
Reaction to make many
copies of the gene


To insert the copies of the


gene into the bacteria we use


plasmids



circular DNA


found in bacteria (not


humans)

Making human insulin
from bacteria:


4.
Remove plasmids from
bacteria and use the same
restriction enzyme to cut
insulin gene out of the
plasmid


sticky ends are left
over with nonpaired bases

5.
Add broken plasmids to
foreign DNA to make a
recombinant DNA
molecule
(held together by convalent
bonds formed with ligase)

6.
Insert plasmid into the
bacteria. When the bacteria
reproduce by dividing, the
human insulin gene is also
reproduced, giving rise to
offspring that are able to
produce human insulin.



How can we use genetic engineering to get
this cow to produce more milk?


Increasing milk
production with rBGH






Using the same process to


make insulin, use bacteria to


make copies of the cow’s


growth hormone.




This hormone is called rBGH


(recombinant Bovine


Growth Hormone)




By injecting it daily into a


cow, you can increase a


cow’s milk production by


10
-
15%.



How can we use genetic engineering to
clone a sheep?

Cloning



using a

cell (except an egg or

sperm cell) from a

multicellular

organism to make

one or more

genetically identical

individuals


Dolly


the first cloned sheep!