PCR A Printing Press for Genes

The PCR process was first published by MuUis in 1985. It uses a mixture of the DNA to be duplicated, heat-stable polymerase, required by the polymerase, the four 2 -deoxyribonucleoside triphosphate building blocks (A,T,C,G), and the oligonucleotide primers (about 20 nucleotides long). There are three main steps in the process  

Denaturation of duplex DNA to two molecules of single-stranded DNA. This typically requires a temperature around 203 °F (95°C) to break all hydrogen bonds between the two strands in the DNA double helix. 

Extension of each growing chain by (heat-stable) DNA polymerase 

Each full PCR cycle doubles DNA content. While 30 cycles can be accomplished in hours and produce, in principle, 10 copies, in practice 10 -10 are achieved since the process is not 100 percent efficient. Eor perspective, it is useful to recall that, in 1455, Johannes Gutenberg printed the very first book using movable type. Relieving monks of the drudgery of handwritten manuscripts and making books widely available, the printing press revolutionized human culture. PCR has already had 

Following years of litigation, Cetus sold all of its PCR intellectual property to Roche pharmaceuticals in 1992 for 300 million and settled with Kary MulHs for 10,000. In 1993 he shared the Nobel Prize in chemistry with Michael Smith of the University of British Columbia for the development of site-directed mutagenesis. 

---