POLYMERASE CHAIN REACTION

Name: Kerry Mullis 

Born: December 1944 

Year Of Scientific Discovery: 1985

POLYMERASE CHAIN REACTION                                                

A method of amplifying DNA was created by Kerry Mullis in the year 1985.

The reaction occurs in an apparatus known as a thermal cycler and uses different temperatures to control the process of DNA replication through the following steps: 

Taq polymeraseè This is an enzyme obtained from the thermophilic (heat loving) bacterium Thermus aquaticus

This particular processing technique is used to generate large amounts of a specific sequence of DNA from a small sample. 

What is so valuable about Polymerase Chain Reaction?

      PCR made a large impact specifically within the biotechnolgy world. It was used to detect genetic disorders, the presece of viruses, finger print scanning within forensic science and the Human Genome Project 

HOW DOES IT WORK?

1.     Denaturation – DNA sample is heated (~90ºC) to separate the two strands

2.     Annealing – The temperature is dropped to approximately to 55ºC) this allows the primers to re- anneal  or to form hydrogen bonds once again (primers designate sequence to be copied)

3.     Elongation – The sample is then heated towards a suitable temperature condition that will allow Taq polymerase a special enzyme which facilitates the process of synthesizing the mRNA strand.

 As this enzyme’s optimal temperature is approximately 75ºC, it is able to function at the high temperatures used in PCR without destroying the protein/ denaturing it.