Polymerase Chain Reaction (PCR): Difference between revisions

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Polymerase Chain Reaction (PCR) is a technique used for the [[Amplification|amplification]] and identification of [[DNA|DNA]] or [[RNA|RNA]]. Also see [[MRNA|mRNA]]  
Polymerase Chain Reaction (PCR) is a technique used for the [[Amplification|amplification]] and identification of [[DNA|DNA]] or [[RNA|RNA]]. Also see [[MRNA|mRNA]].


PCR has three main stages:  
PCR has three main stages:  


1. Heat DNA to 95°C to melt the strands  
1. Heat [[DNA|DNA]] to 95°C to melt the strands  


2. Cool to 50 - 65°C to allow [[primers|primers]] to anneal  
2. Cool to 50 - 65°C to allow [[Primers|primers]] to anneal  


3. Heat to 72°C to allow [[Elongation|elongation]]  
3. Heat to 72°C to allow [[Elongation|elongation]]  


The most important part of the PCR&nbsp;reaction is the initial design of the [[primers|primer]]. This [[primers|primer]] is normally between 18 to 20 base pairs in length and must be completely&nbsp;complimentary to the [[DNA|DNA]] at the start of the region you are interested in amplyfing. Included in the experiment must be both the forward and reverse primers. <br>  
The most important part of the PCR&nbsp;reaction is the initial design of the [[primers|primers]]. The&nbsp;[[primers|primers]] are normally between 18 to 20 base pairs in length and must be completely&nbsp;complimentary to the [[DNA|DNA]] at the start of the region you are interested in amplyfing. Included in the experiment must be both the forward and reverse primers. <br>  


PCR is carried out in a [[thermal cycler|thermal cycler]] and the enzyme '[[Taq Polymerase|Taq Polymerase]]' is&nbsp;used as it is [[Thermostable|thermostable]], therefore&nbsp;is not denatured at the high temperatures. Pfu (''[[Pyrococcus furiosus|Pyrococcus furiosus]]'') [[DNA Polymerase|DNA&nbsp;Polymerase]] can also be used as it has better thermostability than [[Taq Polymerase|Taq Polymerase]] and it possesses 3' to 5' [[proof reading|proof reading]] activity.  
PCR is carried out in a [[Thermal cycler|thermal cycler]] and the [[Enzyme|enzyme]] '[[Taq Polymerase|Taq Polymerase]]' is&nbsp;used as it is [[Thermostable|thermostable]], therefore&nbsp;is not denatured at the high temperatures. [[Pfu|Pfu]] (''[[Pyrococcus furiosus|Pyrococcus furiosus]]'') [[DNA Polymerase|DNA&nbsp;Polymerase]] can also be used as it has better thermostability than [[Taq Polymerase|Taq Polymerase]] and it possesses 3' to 5' [[Proof reading|proof reading]] activity.  


The technique was developed by Kary Mulis in 1983 for which he was awarded the [[Nobel Prize|Nobel Prize]] in Chemistry in 1993.  
The technique was developed by Kary Mulis in 1983 for which he was awarded the [[Nobel Prize|Nobel Prize]] in Chemistry in 1993.  

Revision as of 22:16, 6 November 2010

Polymerase Chain Reaction (PCR) is a technique used for the amplification and identification of DNA or RNA. Also see mRNA.

PCR has three main stages:

1. Heat DNA to 95°C to melt the strands

2. Cool to 50 - 65°C to allow primers to anneal

3. Heat to 72°C to allow elongation

The most important part of the PCR reaction is the initial design of the primers. The primers are normally between 18 to 20 base pairs in length and must be completely complimentary to the DNA at the start of the region you are interested in amplyfing. Included in the experiment must be both the forward and reverse primers.

PCR is carried out in a thermal cycler and the enzyme 'Taq Polymerase' is used as it is thermostable, therefore is not denatured at the high temperatures. Pfu (Pyrococcus furiosus) DNA Polymerase can also be used as it has better thermostability than Taq Polymerase and it possesses 3' to 5' proof reading activity.

The technique was developed by Kary Mulis in 1983 for which he was awarded the Nobel Prize in Chemistry in 1993.

PCR can be done using water baths at varying temperatures.[1]