Question

DNA polymerase enzyme used in PCR is isolated from

• A. E. coli
• B. Salmonella typhimurium
• C. None of the above
• D. Thermus aquaticus

Answer 1

The correct option is D

Thermus aquaticus

Role of Taq polymerase in PCR is as follows:

• Taq polymerase is a thermostable enzyme that is used to catalyse the addition of dNTPs to the primer thus helping in the extension of the DNA strand.
• This process of extension is carried out at 72°C and only a thermostable DNA polymerase could carry out the reaction without getting denatured. Therefore this enzyme is isolated from a bacteria, Thermus aquaticus that lives at high temperatures (thermophilic bacteria).

Hence the correct option is
a. Thermus aquaticus