In Biotechnology there is a process known as PCR. PCR, or Polumerase Chain Reaction is widely performed through a series of heating cycles that pull apart, duplicate, and fuse back together the two strands of a DNA double helix, PCR creates new copies of DNA that are identical to the original.
Traditional PCR requires the material be heated to about 95C, wherupon the DNA strands seperate, or ‘denature’. The sample is then cooled a bit so the strands will anneal to ‘primers’, which are short DNA strands designed to bond to specific sections of the DNA strand. The sample is heated slightly more (72C) and activates an enzyme called polymerase that attaches itself to the end of the primer. The polymerase “extends” the primer’s length based on the original DNA, thus recreating the desired sequence.
During this “extension” step, the polymerase reacts with the original copy to produce a new chain of DNA, thus the name Polymerase Chain Reaction. Since this process happens for both of the original DNA strands, the amount of DNA is doubled after one PCR cycle. Over many cycles, PCR exponentially expands the amount of DNA you were started with.