Introduction to PCR

In this video, we will introduce the basics of the Polymerase Chain Reaction, or PCR. We’ll review the history of PCR, typical components and principles of the reaction, polymerases available, PCR reaction types, and the various applications of this widely used molecular biology technique. What is PCR? It is one of the most common techniques used in molecular biology. It is a quick way to amplify minute quantities of DNA to millions of copies. DNA polymerases used in PCR originate from thermophilic microorganisms and therefore are heat-resistant. Their ability to withstand high temperatures is important in PCR because high temperatures are needed to melt or separate the double-stranded DNA. This separation then allows the DNA polymerase to synthesize complementary DNA strands. The technique was first published in 1985. In 1993, a Nobel Prize was awarded to Kary Mullis for his invention of the PCR method. Researchers had been performing similar reactions since 1971 when Norwegian scientist Kjell Kleppe and colleagues described an enzymatic process to replicate a short DNA template using primers in vitro. In 1988, the first PCR machine was introduced to the market. Since then, many improvements have been made to the reagents and instrumentation researchers use to perform PCR. These improvements in PCR technology have allowed for powerful achievements with far-reaching implications, such as the sequencing of the first complete individual human genome.