Polymerase Chain Reaction

PCR... Whaaaat?

• Founded by Kary Mullis in 1984

• He wished to bracket the desired section of DNA with primers and copy the desired fragment with DNA polymerase.

• Essentially “Genetic Photocopying”

The “Deets”

Ta• Primers • Taq polymerase --> High

Temperatures•  Free nucleotides

Besides DNA, there are 3 main ingredients::

Cycle 1• A temperature "yoyo"• Taq polymerase --> 3' - 5'

The "Deets" (cont'd)Cycle 2 - repeat cycle 1 :)- 4 copies of target DNA

Cycle 3 - exactly like cycles 1 and 2- 8 copies of target DNANote** only 2 of these copies are of the target fragment on its own.   

After 32 cycles of PCR there will be:

4 294 967 296 

copies of target DNA 

What the Cycles Look Like

 

Works Cited

“Polymerase Chain Reaction.” Contexo.info. Web Page. 19 Nov 2010.• http://www.contexo.info/DNA_Basics/polymerase_chain_reaction.htm. • “PCR.” Enigma Diagnostics. 2009. Web Page. 28 Nov 2010. • http://www.enigmadiagnostics.com/template2.php?page=technology.php&m=2. • “The Polymerase Chain Reaction.” Sumanasinc.com. Web Page. 19 Nov 2010.• http://www.sumanasinc.com/webcontent/animations/content/pcr.html. • “Polymerase Chain Reaction.” Genetics Wiki. 30 Sept 2009. Web Page. 19 Nov 2010.• http://wiki.cstl.semo.edu/agathman/PCR.ashx • “Scientist Develops Salmonella Test That Makes Food Safer, Reduces Recalls.” Meat • and Poultry Online. 24 Nov 2010. Web Page. 25 Nov 2010. • http://www.meatandpoultryonline.com/article.mvc/Scientist-Develops- Salmonella-Test-

0001?atc~c=771+s=773+r=001+l=a&VNETCOOKIE=NO.• “Using molecular marker technology in studies on plant genetic diversity: DNA-based • technologies; PCR based technologies: PCR basics. Cornell University. 2003. • Web Page. 28 Nov 2010. • www.bioversityinternational.org/.../MolMarkers%20Vol1%20III%20PCR%20basics.pdf.• “What is a Thermal Cycler.” Thermal Cycler. Web Page. 28 Nov 2010. • http://thermalcycler.net/.

3 Major Steps

Each Cycle of Polymerase Chain Reaction can be split into 3 basic steps:

         Step 1: Denaturation

 

Step 2: Annealing

 

Step 3: Extension

Further Explanation  

http://www.sumanasinc.com/webcontent/animations/content/pcr.html

Heavy Machinery

• Thermal Cycler is used in the lab to make large numbers of DNA fragments

Look Familiar Much?

• DNA replication and PCR are very similar....they both:

• need Template stands• Needs polymerase enzyme• Both use primers

Applying PCR to the Real World

• Human Genome Project• DNA Fingerprinting / Forensics • Mutation Screening• Genealogical Testing / Genetic Disorders• Cloning• Detection of viruses (namely HIV and AIDS)

... Just to name a few

PCR in the NEWS!

• Scientist at University of Missouri using PCR to detect salmonella in

eggs and poultry

THE END

And now for your listening pleasure…

http://www.cnpg.com/video/flatfiles/539/