1. Restriction Enzymes and Plasmid Mapping

2. Recall Gene Cloning Vocabulary
The original plasmid is called the cloning vector
DNA molecule that can carry foreign DNA into a cell and replicate there
After insertion of the gene of interest into the plasmid the plasmid is called recombinant DNA

3. Recall Gene Cloning Vocabulary
Restriction Enzymes
Molecular “scissors”
Cut DNA molecule at SPECIFIC location (locus) called the restriction site
The terms “cut,” digest,” or restrict” mean to use a restriction enzyme
This results in DNA fragments (pieces)

4. Restriction Enzyme Digest  different length pieces are made

5. Gel electrophoresis markers are used for size identification of each DNA fragment

6. Restriction Fragment Length Polymorphisms (RFLPs) provides a map of a plasmid
A map gives the number and position of restriction enzyme cutting sites
A maps gives the size of DNA fragments

7. Remember Plasmid is Circular
Circular DNA: the number of fragments = number (N) of cutting sites
versus
Linear DNA: number of fragments=N+1

8. Linear DNA
Plasmid DNA
EcoRI
BamHI
EcoRI
BamHI
2 cutting sites
2 fragments
2 cutting sites
3 fragments