BIOLOGY 201L Chapter Notes - Chapter 10: Polyacrylamide Gel Electrophoresis, Hybridization Probe, Southern Blot
Document Summary
Recombinant dna tech has been used to detect mutations in human genes that are responsible for inherited disorders; used to produce pharmaceuticals (insulin); used to identify crime suspects; (cid:373)ake lau(cid:374)dry deterge(cid:374)t . Restriction nucleases cut double stranded dna at particular sequences. They also restrict transfer of dna between strains of bacteria. Target sequences are 4-8 nucleotide pairs long, so many sites of cleavage will occur. They can reliably generate the same set of dna fragments. Dna fragments can be separated from one another based on length by gel electrophoresis. Dna fragments are loaded at one end of agarose or polyacrylamide gel. Voltage applied across gel, negatively charged dna fragments migrate toward positive electrode. To isolate a fragment, small section of gel that has the band is cut out and dna is extracted. Gel can be exposed to a dye that fluoresces under uv light when bound to dna.
