Restriction Enzymes and Plasmid Mapping

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

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)

Restriction Enzyme Digest  different length pieces are made

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

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

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

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