LIFESCI 3 Lecture Notes - Lecture 11: Phosphodiester Bond, Nucleophile, Dideoxynucleotide
Document Summary
Lecture 11 (2/3/17: pcr in the field, step 1. Isolate dna samples: what biological specimens would yield dna at a crime scene, white blood cells, semen, skin, lip pritns, saliva. If you find just a few cells, that would not be enough dna. We need to make more of it: step 2. Make copies of specific portions of dna: to make more dna, use the polymerase chain reaction (pcr, pcr amplifies specific regions of dna for comparison between individuals, for dna profiling, short tandem repeats (strs) are used, step 3. Isolate dna: use pcr to amplify strs, compare sizes of strs using gel electrophoresis, using pcr for criminal investigations, set up a pcr reaction using primers that bracket the vntr (variable. Number tandem repeats) locus: pcr produces a pair of bands of amplified dna, one maternal and one paternal. The length of the amplified dna will depend on the exact number of repeats at the locus: more loci examined=more confidence.
