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Polymerase Chain Reaction (PCR) is a technique which help us amplify small amounts of DNA and end up with large amounts of it... it was invented by Kary Mullis
This is a rough sketch of how PCR works:
First the DNA that is to be replicated is placed in a solution containing heat-resistant DNA Polymerase (found in bacteria residing in hot springs) and free-floating nucleotides.*** The heat breaks the hydrogen bonds that hold the nucleotides together, and the DNA falls apart. Then the solution is allowed to cool, and DNA polymerase goes to action replicating two DNA strands, forming two new sections of DNA. This process can be repeated many times, increasing the amount of DNA exponentially, as the copies are copied themselves. The new DNA strands are perfect replicas of the original. ****There must also be two single strands of DNA, that complement the original in both the sense (forward) and antisense direction. The free-floating nucleotides cannot randomly bind and extend on there own, they must elongate a primer (the single strands) (PCR) Polymerase Chain Reaction makes lots of copies of DNA's when the DNA sample is too small to analyse. * The small DNA sample is heated up to 95˚C to break the hydrogen bonds between the bases so that the 2 strands partially separate. * DNA primers which are complementary DNA strands are added and cooled up to 55˚C. They will tell the enzyme (DNA polymerase) where to start copying. * DNA polymerase and free DNA nucleotides are added and heated up to 70˚C. Template strand(1 strand) or (original strand) is used to make the new DNA. Free DNA nucleotides base pair with the complementary template strand. * The DNA polymerase sticksthe free nucleotides to the complementary strandforming a new DNA Modification to the above:
While the above answer is correct in general, a couple of specific technical details are off. Firstly, the temperature in the second step does not go to 55 degrees C automatically. It is a variable temperature dependent on the temperature required for the primers to anneal to the main DNA template. The scale typically used is that of Tm (the melting tempraature). It is the point where half of the total primers in solution is connected to the coresponding main strand. In setting up the PCR reaction, one typically goes 5 degrees below that point to maximize effectiveness while ensureing that the space is open for annealing to the primer.
Secondly, the enlongation step is not run at 70 degrees C, but rather 72.
Wiki User
∙ 15y ago
Wiki User
∙ 9y agoPolymerase chain reactions (PCR) are what allow for small samples of DNA to replicate numerous times and eventually become plentiful enough for proper analysis.
PCR is useful in DNA fingerprinting as they provide a quick and efficient way to replicate DNA. Generally, various enzymes and conditions are required for traditional methods of replication (enzymes like gyrase and helicase). However PCR allows us to bypass many of these requirements and simply create large quantities of the same genetic sequence.
After replicating the DNA millions of times, the sequence in question can be analysed and further sequenced (through a gel, or other means).
Wiki User
∙ 7y agoPolymerase chain reaction is used to make numerous copies of small samples of DNA for analysis. This is useful when there is a very small or limited sample of DNA available for analysis
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What is pcr and types of pcr?
PCR is a biotechnological method to amplify your gene (DNA) of your interest. It produce millions of your DNA fragments hence used in cloning. There are variants of this method using the same thermocycling principle such as touch down PCR, gradient PCR, RFLP, multiplex PCR, Q PCR, RT PCR and so on.
How does a DNA molecule act as a template?
Template DNA is a DNA you want to amplify. So you should know what you are amplifying before a PCR or you can make it by sequencing your PCR product.
Why is PCR called a chain reaction?
PCR can repeatedly duplicate a DNA (or RNA) fragment, so it's a chain reaction. After each cycle, PCR can repeat and repeat again to produce many copies of the same DNA segment.
What is the sequence of the template DNA?
What do you really want to ask? template DNA is a DNA you want to amplify. So you should know what you are amplifying before a PCR or you can make it by sequencing your PCR product.
Why is it important that RNA carries DNA instructions out of nucleus?
DNA carries the genetic information of a cell. WHen this information is needed, the genes are transferred to RNA So, it is important.
What is pcr and types of pcr?
PCR is a biotechnological method to amplify your gene (DNA) of your interest. It produce millions of your DNA fragments hence used in cloning. There are variants of this method using the same thermocycling principle such as touch down PCR, gradient PCR, RFLP, multiplex PCR, Q PCR, RT PCR and so on.
Why is crossing over so important?
It increases genetic variation in organisms
Why fertilized human is important?
Fertilization is important so species can have genetic variation. It is also important so the species can pass on their genes.
Why are animal breed societies so important?
becuase they provide expert advice to owners who may not know how to look after their animals. they also provide money for research to put an end to genetic desieases
How does a DNA molecule act as a template?
Template DNA is a DNA you want to amplify. So you should know what you are amplifying before a PCR or you can make it by sequencing your PCR product.
Why is PCR called a chain reaction?
PCR can repeatedly duplicate a DNA (or RNA) fragment, so it's a chain reaction. After each cycle, PCR can repeat and repeat again to produce many copies of the same DNA segment.
What is chimera and why so important?
A chimera is an organism with cells from two or more genetically distinct individuals. They are important because studying chimeras can provide insights into development, organ transplantation, and disease. They also have the potential to create new therapeutic techniques and advance genetic research.
Why is it important to research a medical career?
so you can get paid
Why is random sampling so important for research?
sampling is very important for researcher
Why are scientists so interested in extremophiles?
Extreme environments have been useful to scientists in inventing PCR. It was in an extreme environment like the geysers of Yellowstone that a scientist discovered that a bacteria was living in the extremely hot water and yet still could function. Before PCR we knew we could separate a strand of DNA by heating it, but there was no polymerase to duplicate it that would work at such a high temperature. The bacteria in the hot water had a polymerase that would. So now scientists use that to do PCR and create many copies of DNA.
Why is PCR useful?
PCR polymerase chain reaction allows for the scientist to put in a small amount of DNA and to receive a large amount of DNA back. It amplifies the DNA. Each cycle doubles the amount of DNA template.
What is the difference between Clean-room and sterile-room?
You may want to double-check this, but I believe PCR-clean simply means that there are no DNases or RNases on the item, but they still could have nucleic acid on them. Essentially there is nothing on them that would interfere with nucleic acid amplification achieved with PCR, but any genetic material they may have will be amplified. Sterile means that there is absolutely no genetic material on the item itself (usually achieved via autoclaving where the temperatures climb so high that they would denature the DNases and RNases anyway). Nutshell: PCR-clean = wiping with RNA away and DNA away Sterile = bleaching and autoclaving
