A more efficient and rapid method of amplifying DNA is by the Polymerase
chain reaction (PCR). In this process traces [1] of DNA can be amplified
millions of times very rapidly in a test tube.
* Short segments of single stranded DNA known as bind primers [2](start
sequences) and free nucleotides [3] are added to the sample of DNA
* The sample of DNA is denatured by heating. As the mixture cools the
primers bind to regions at either end of the now single strands of the DNA
sample. The polymerase [4] enzyme [5] completes the synthesis of the second
strand using the nucleotides in the mixture.
* The process is repeated for many cycles to produce quantities of DNA.
Each cycle of replication takes about 5 minutes.
Watch the video that shows polymerase chain reaction machines in a DNA
testing laboratory.
