The Steps to DNA Fingerprinting
first step is to get the DNA from the specimen. The sample of DNA can be obtained from skin, hair, nails, saliva, or
blood. Once the DNA is taken enzymes are used to cut it. The cuts are then made in specific spots. The enzymes are designed to cut in specific spots according
to their genetic design. The scientist has to be careful in which enzyme
they use because each one cuts at specific spots. Some restriction enzymes cut
leaving blunt ends and some leave sticky ends. The sticky ends are preferred
because they are easier to work with because they attach to other pieces of DNA easily.
The blunt ends are more difficult to use because their ends do not match with other ends of other DNA. A sticky end could look like this: 5’ AGAAGAGAGAGAG
blunt end could look like: 5’TTTTTTT
The DNA is then sorted by gel electrophoresis. The following step is to transfer the piece of DNA to
a nylon sheet and then it is soaked. This hour long process is called
capillary action. After the transfer is complete the fragments are treated with
ultra violet light which crosses links the DNA to the membrane. The next step
is probing. The DNA is the annealed using a probe. The last thing to do is visualize the final product using an autoradiograph.