Biotechnology Gel Electrophoresis Using the new to improve
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 § 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.
Examples: Interpreting DNA Fingerprints
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 3: Who is the father? How do you know?
Example 4: Who are the parents of this soldier? How do you know? http: //www. glencoe. com/qe/images/b 136/q 4318/ch 13_0_c. gif
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