DNA Fingerprinting(RFLP Electrophoresis)

DNA Double HelixFour nucleotide bases make up the chains of the double helix

DNA FingerprintingRFLP (Restriction Fragment Length Polymorphism)

1 microliter (ul) =

10-6 liters =

0.000001 liters

1 millionth of a liter

Restriction Enzymes cut DNA at specific recognition sequences – typically palindromes.

Restriction enzymes are also called restriction endonucleases and the process of cutting the DNA is

called a restriction digest .

DNA samples with the EcoR1 and Pst1 recognition sequences at different places will be cut into fragments of

different lengths.

Fragments can then be separated by size to create an RFLP banding pattern using Gel Electrophoresis.

DNA is negatively charged so the fragments are drawn through the agarose gel towards the positive electrode. Large fragments move more slowly, smaller fragments

move more quickly. The pool of DNA fragments separates into discrete bands creating an RFLP DNA Fingerprint.

Gel Electrophoresis

http://upload.wikimedia.org/wikipedia/commons/e/ec/AgaroseGel.jpg

Negative (-) Electrode

CS S1 S2 S3 S4 S5

WELLS (lanes)

Positive (+) Electrode