Any recombinant DNA with desired gene is required in billion

Any recombinant DNA with desired gene is required in billion copies for commercial use. How is the amplification done? Explain.

Amplification of gene is done using Polymerase Chain Reaction (PCR).
Polymerase Chain Reaction (PCR) is best defined as in vitro process of DNA replication . This technique was developed by Kary Mullis in 1985 who received Nobel Prize for it in 1993.
The basic requirements of a PCR reaction are as follows:
(a) DNA Template The double stranded DNA that needs to be amplified. .
(b) Primers These are chemically synthesised oligonucleotides (short segment of DNA) that are complementary to the regions of DNA template.
© Enzymes Two commonly used enzymes in PCR reaction are:
• Taq Polymerase It is isolated from a thermophilic bacterium, i.e. Thermus aquations. It has a property to remain active during the high temperature induced denaturation of double stranded DNA. It also helps in the amplification of a segment of DNA.
• Vent Polymerase (isolated from Thermococcus litoralis).
(d) Nucleotide bases These are added by DNA polymerase to the growing chain.