What is true about the DNA polymerase utilized in PCR?

The correct answer is that the enzyme should not be heat labile. In the context of Polymerase Chain Reaction (PCR), a critical feature of the DNA polymerase used is its ability to withstand the high temperatures involved in the denaturation step, typically around 95°C. Standard DNA polymerases, such as Taq polymerase derived from Thermus aquaticus, are thermostable, allowing them to maintain functionality and efficiency through multiple cycles of denaturation and synthesis without inactivation.

In PCR, the process involves repeated cycles of heating and cooling. During the denaturation phase, the double-stranded DNA separates, and any heat labile enzyme would become inactive and unable to synthesize new DNA strands in subsequent cooling and elongation phases. Hence, using a heat-stable DNA polymerase is essential for the success of PCR, as it ensures that the enzyme remains active throughout the reaction cycles.

The other options present criteria that do not align with the needs for effective PCR. Nucleotide diphosphates would not be accepted since DNA polymerases require deoxynucleotide triphosphates (dNTPs) for DNA synthesis. Low fidelity is also undesirable in PCR, as high-fidelity polymerases are preferred for accurate amplification and reduced mutation rates