100 likes | 131 Views
Biotechnology: Gel Electrophoresis. Using the new to improve the old…. Our knowledge of the structure and function of DNA is fairly new information. Watson & Crick - 1953 However, in a short amount of time, our DNA knowledge has been used to: Improve identification methods of criminals
E N D
Using the new to improve the old….. • Our knowledge of the structure and function of DNA is fairly new information. • Watson & Crick - 1953 • However, in a short amount of time, our DNA knowledge has been used to: • Improve identification methods of criminals • Determine maternity/paternity • Bioengineer products • Blood typing was first used for some of these purposes, but it has limited capability because it is not specific to each person.
Gel Electrophoresis (DNA Fingerprinting) • Every person has a unique sequence of DNA • Restriction enzymes can be used to cut a strand of DNA into several pieces • e.g., enzyme cuts when it encounters GAATTC • A DNA fingerprint is a unique “picture” of a person’s cut up DNA fragments that are then separated by size Who took Jimmy's lollipop?
The short version of how DNA fingerprints are made DNA is (-) charged. When you turn on the gel, the DNA samples move across to the (+) side. Because the gel is porous (contains small holes), large fragments get stuck and don’t move far whereas small fragments move farther.
Example 1: Who left the blood stain? How do you know? http://www.biologycorner.com/resources/DNAfinger.gif
Example 2: Who are the children of these parents http://www.scq.ubc.ca/a-brief-tour-of-dna-fingerprinting/
Example 4: Who are the parents of this soldier? How do you know? http://www.glencoe.com/qe/images/b136/q4318/ch13_0_c.gif