BIO374H5 Chapter Notes - Chapter 8: Thermal Cycler, Amniocentesis, Surrogacy
Document Summary
Each human being carries a unique set of genes (same dna chemical. Forensic science intersection of law and science structure but different order of base pairs in chromosomes) Uniform nature in individual & genetic variability b/w individuals. 2 main types of forensic dna testing: restriction fragment length polymorphism (rflp) based. Need dna intact + undegraded: polymerase chain reaction (pcr) based. But extremely sensitive to foreign dna contamination. Variable number tandem repeats (vntrs) inactive dna containing repeated sequences (b/w 1-100bp) determine genetic identity. Uniqueness of vntrs=scientific marker of identity (finger print) Dna fingerprints produced by pcr = restricted to detecting presence of microsatellites (1-6 nucleotide repeats dispersed throughout chromosomes); probes used to identify. Short tandem repeat (str) small size of repeated segments. 13 unique strs selected to test for dna profiles contained within combined dna index system(codis: preparing a dna fingerprint. Detergents to chemically wash away unwanted cellular material + protein- and rna- digesting enzymes + precipitation in ethanol.
