**5. Magnitude of amplification**

Multiple cycling steps of a PCR can exponentially increase the copies of target DNA template to millions. The number of DNA copies produced by a PCR can be calculated using the formula "2n ", where n is the number of cycles [27, 28]. For example, a PCR set for 36 cycles results in 68 billion copies of the template. Under optimal conditions, even with minimal efficiency, a PCR in 50 ml volume may produce 0.2 mg of 150 bp DNA from 100 template molecules after 35–40 cycles, with the molar weight of the fragment equal to 99,000 Da.
