Sarah+PCR+and+DNA+notes

Notes on DNA: DNA forensics:

PCR: - polymerase chain reaction - used to make copies of the DNA so that you have a larger sample - advantage: the amplification process can be limited to specific areas of the sequence - amplification process: you put the solution in the test tube, then you put it into a machine that does all of the steps in about 12 hours - step 1: denaturation through heat where you break apart the DNA into two separate strands - step 2: annealing, where you copy the DNA (there is a primer where you put it on the DNA stran) - step 3: extension where the DNA extends (adds on bases to make base pairs) - amplification: each DNA splits and forms two so at the end, you have a lot of DNA -

DNA: - genetic instructions - DNA ca be found in cells - Your DNA is the same no matter what cell you use - The mitochondrial DNA only comes from your mother and the nuclear DNA comes from both the mother and the father - DNA is in a chromosome - There are four DNA base pairs (A=adenine, T=thymine, C=cytosine, G=guanine) - Types of objects where DNA may be found: o Blood stains o Semen stains o Chewing gum o Stamps and envelopes o Penile swabs o Plant material o Sweaty clothing o Bone o Hair o Fingernail scraping o Saliva o Animal material