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PCR - Polymerase Chain Reaction. Allows for amplification of a DNA sequence by repeated cycles of replication. very similar to DeptNA replication in cell, except: DNA strands separated by heat synthetic DNA primers used instead of RNA primers Taq Polymerase instead of DNAP I & III
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PCR - Polymerase Chain Reaction Allows for amplification of a DNA sequence by repeated cycles of replication
very similar to DeptNA replication in cell, except: • DNA strands separated by heat • synthetic DNA primers used instead of RNA primers • Taq Polymerase instead of DNAP I & III • 2 parent strands synthesised continuously
PCR allows a single sequence of DNA to be amplified to millions of copies in a short period of time • used in forensic criminal investigations, medical diagnostics & genetic research • Cutting, Pasting, & Copying DNA & the Recombinant DNA Controversy
RFLP - Restriction Fragment Length Polymorphism using restriction enzymes to digest DNA fragments and compare differences between individuals
Polymorphism • difference in DNA sequence between individuals of same species • fragments of DNA have microsatellites or VNTR’s (variable number tandem repeats), short sequences (2-6 bp) that repeat over and over
length and number of VNTR’s are different in every person except identical twins • known as ‘DNA fingerprinting’ • restriction enzymes will give different length DNA fragment for each person
Southern Blotting • transfers DNA from gel onto nylon membrane while keeping DNA fragments in place • probe the membrane with radioactive labelled complimentary sequence • probe will attach to DNA at certain locations (hybridization)
when exposed to x-ray film, places where probe attached to DNA shows dark bands (audiogram) • pattern on audiogram can be used to compare suspect’s DNA to DNA found at crime scene • Use of DNA Analysis in Identification, Health, & Human Origins