True about polymerase chain reaction (PCR) -

In PCR, thermostable DNA polymerase (Taq polymerase) is used because, in PCR, DNA is to be heated upto 94-95°C for separation of two strands of DNA. Each cycle doubles the amount of DNA in the sample, leading to exponential increase (not additive) with the repeated cycle of amplification. Specific primers are required, that have a nucleotide sequence complementary to flanking region of target DNA. Double-stranded DNA sequence is amplified in PCR.