The document describes the Southern blot technique, which was discovered in 1973 by Edwin Southern at Edinburgh University. The Southern blot allows for the detection of specific DNA sequences and involves separating DNA fragments using gel electrophoresis, transferring them to a membrane, incubating the membrane with a probe that binds to complementary DNA sequences, and revealing the location of the probe using a colorless substrate and X-ray film.

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 