Polymerase chain reaction principles and its applications

Abstract

The polymerase chain reaction (PCR) is to amplify millions of copies of a specific region of a DNA (target) from a complex DNA template through the process of PCR cycling in the presence of PCR reaction mixtures. As the PCR progresses, the amplified target sequence will be utilized as a template in the subsequent cycles and the target sequence is exponentially amplified. PCR was discovered by Dr. Kerry Mullis in 1983 at the Cetus Corporation in Emeryville, CA and he was awarded the Nobel Prize in Chemistry for his work on PCR in 1993. PCR is now commonly used for diagnostic purposes in the medical and biological research. Moreover, the in vitro DNA synthesis usingtwo primers was initiated by Gobind Khorana in 1971, but the main constraints is that primer synthesis and polymerase purification issues. Though the previous techniques were used for isolating a specific gene by gene cloning method, but it‘s a laborious and time consuming processes. Whereas in the direct sequencing strategy for the gene of interest is quite difficult because of the complexity of the human genome and the primers were added to block the progression of the synthesis of the first primer.