1. By: Corey Cotsonas

2.  Help to find molecular weight of a restriction
fragment
 Detection of a specific DNA sequence

3.  Discovered by Edwin Southern in 1973
 Discovered at Edinburgh University
 Edwin’s work wasn’t published until 1975

7.  1) DNA and a restriction enzyme are mixed
◦ They are then separated by gel electrophoresis
◦ DNA is separated into single strands through
incubation with NaOH
 2) DNA is transferred onto special blotting
paper
◦ DNA fragments remain separated

8.  3) The blot is incubated with copies of a
probe (single stranded DNA)
◦ Probe will bind with complimentary DNA sequence
◦ Creates double-stranded DNA molecule
 4) Location of probe is shown
◦ Revealed by incubating probe with colorless
substrate, and exposes X-ray film

9.  http://highered.mcgraw-
hill.com/sites/0072556781/student_view0/chapter14/animation_quiz_5.html
 http://www.sinauer.com/cooper5e/animation0411.html

10.  Northern and Southern Blot:
◦ Both use gel electrophoresis
◦ Northern blot identifies sequences in RNA and
separates RNA fragments using the gel
Northern Blot 

11.  Western and Southern Blot:
◦ Also uses gel electrophoresis
◦ Western Blot used to find proteins and arrange
them by size and shape.
Western Blot 