Polymerase Chain Reaction a.k.a. “How’d they get all that DNA from just a little blood?”

What does PCR stand for? Polymerase Chain Reaction Developed by Kary Mullis – Nobel Prize

What is the goal of PCR? To make many copies of a small section of DNA. DNA Synthesis in vitro (in a test tube).

How does PCR work? Very Similar to DNA Synthesis Very Similar to DNA Synthesis

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What is needed for a PCR reaction? DNA template – DNA to be copied; “target sequence”

What is needed for a PCR reaction? PCR primers – short DNA sequences; complimentary to beginning and end of target sequence

What is needed for a PCR reaction? Taq DNA Polymerase - copies DNA - Can survive hot temperatures needed in PCR reaction - From heat loving bacteria Thermus aquaticus.

What is needed for a PCR reaction? Nucleotides – building blocks of DNA Thermalcycler – computerized to change temperatures

What is needed for a PCR reaction? MgCl 2 – part of buffer, all enzymes need the correct buffer (acid + salts) to work MgCl 2

What are the 3 main steps of PCR? Denaturing – DNA strands separate at hydrogen bonds Temperature = 95 0 C

What are the 3 main steps of PCR? Annealing – Primers bind Temperature is dependent on primer sequence Annealing temperature = 3(G+C) + 2(A+T) # of H-bonds between nucleotides

What are the 3 main steps of PCR? Extension – DNA is copied Temperature = 72 0 C

PCR Reaction Summary 1. Denaturing 2. Annealing 3. Extension 30 cycles

How many times can target DNA be copied? DNALC

What would someone do with PCR? Forensics Identification of corpses or body parts. Identification of corpses or body parts. Analysis of pathogens. Analysis of pathogens. Eliminate or link suspects to scene of crime through a sample (blood, human hair, skin, semen) left at scene or circumstantial links (pet hair, plant parts). Eliminate or link suspects to scene of crime through a sample (blood, human hair, skin, semen) left at scene or circumstantial links (pet hair, plant parts).

What would someone do with PCR? Medical (genotyping) Genetic diseases identified pre- or post-natally. Genetic diseases identified pre- or post-natally. Cancers identified and classified. Cancers identified and classified. Identifying bacterial or viral strains for proper treatment. Identifying bacterial or viral strains for proper treatment.

What would someone do with PCR? Food Science Samples can be tested for genetic engineering traits. Samples can be tested for genetic engineering traits. Bacterial contaminants and source of contamination can be quickly identified. Bacterial contaminants and source of contamination can be quickly identified. Pedigrees and traits of valuable animal food stocks can be verified. Pedigrees and traits of valuable animal food stocks can be verified.

What would someone do with PCR? Relationships Paternity. Paternity. Evolution – developing relationships between organisms or studying extinct species from museum specimens. Evolution – developing relationships between organisms or studying extinct species from museum specimens. Ecology – tracking organisms or defining biodiversity by identifying unique species. Ecology – tracking organisms or defining biodiversity by identifying unique species.

PCR Review Music Video BioRad “When You Need to Find Out Who The Daddy Is” BioRad “GTCA”