The polymerase chain reaction (PCR) is a technique that is used to make multiple copies of a piece of DNA.
PCR is carried out in vitro, but mimics what happens in cells when DNA is copied (replicated) prior to cell division.
How does PCR work?
Next, the temperature is lowered and an order in which these nucleotides are joined to the new strand is determined by the sequence of nucleotides in the original DNA strand which is being copied.(usually Taq polymerase) joins free DNA nucleotides together. The
The result is a double stranded DNA molecule which contains one newly made strand and one original strand.
Next, the newly created double helix is separated (by heating the solution) and the cycle is repeated.
When is PCR used?
PCR can be used for a range of different purposes, for example: