Biotechnology - Ms. Nevel's Biology Website
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Transcript Biotechnology - Ms. Nevel's Biology Website
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/b136/q4318/ch13_0_c.gif