( ...)PCR principles

In April, 1983, Kary Mullis took a drive on a moonlit California mountain road and changed the course of molecular biology. During that drive, he conceived the Polymerase Chain Reaction (PCR). As is shown in the figure, the reaction uses two oligonucleotide primers that hybridize to opposite strands and flank the target DNA sequence that is to be amplified. The elongation of the primers is catalyzed by a heat-stable DNA polymerase (such as Taq DNA Polymerase). A repetitive series of cycles involving template denaturation, primer annealing, and extension of the annealed primers by the polymerase results in exponential accumulation of a specific DNA fragment. The ends of the fragment are defined by the 5' ends of the primers. Because the primer extension products synthesized in a given cycle can serve as a template in the next cycle, the number of target DNA copies approximately doubles every cycle; thus, 20 cycles of PCR yield about a million copies of the target DNA. During the last decade, innovative researchers have continually updated the definition of "PCR applications", increasing the usefulness and scope of the technique. For instance:

Combining reverse transcription and PCR into the RT-PCR technique brought the benefits of PCR to analysis of RNA.

• 
  '"/>

Source:


Page: All 1 2 3 4
Related biology technology :

1. Praise for the principles of Peter