Restriction enzymes are double stranded dna endonucleases. Some have blunt ends, some have 3" sticky ends, some have 5" sticky ends: what do they do, types of ends, calculation of average fragment size: 4n. The n is the length of recognition size. Need to analyze dna after it has been cut with restriction enzyme: basic procedure. Run them on agarose or polyacrylamide gel: basis of separation size. Smaller dna fragments run through faster than larger fragments. Dna amplification 1 molecular cloning: how a plasmid vector works. Amplify dna in bacteria or a bacteriophage. Deal with a plasmid vector that has an f factor and a selectable marker: ligation. Add ligase to get them to come together to form chimeric molecules with plasma dna and human dna: transformation, selection. Select for bacteria that have taken up the plasma dna will get a colony of bacteria that have taken up this plasmid. Dna amplification 2: pcr: primers, thermocycling, chain reaction.