How does PCR work?

PCR stands for polymerase chain reaction. It is a technique used very commonly in molecular biology. It is a way of replicating one strand of DNA into many copies that can then be studied. The components needed in the reaction vessel are:1. the strand of DNA to be replicated2. primers - short strands of RNA needed to begin the replication3. polymerase - the enzyme needed to add the nucleotides onto the DNA chain4. nucleotides - the building blocks of DNAThe reaction takes place in a machine called a thermal cycler, which alters the temperature for each stage of the reactions. This is the sequence of events:1. 95° - the DNA strands separate (denature)2. 55° - the primers bind to the complementary DNA (annealing) 3. 72° - the polymerase adds on nucleotides, copying the DNA strandThe cycle is then repeated, and the amount of DNA doubles each complete cycle.