Question

Explain the amplification of gene of interest using the technique of Polymerase Chain Reaction (PCR).

Hint:

PCR enables rapid and specific amplification of DNA using repeated cycles of denaturation, annealing, and extension.

Answer 1

Polymerase Chain Reaction (PCR) is a technique used to amplify a gene or DNA segment of interest.
Steps of PCR:

1. Denaturation: The double-stranded DNA is heated to \(94^\circ\text{C} - 96^\circ\text{C}\) to separate it into two single strands.
2. Annealing: The temperature is lowered to \(50^\circ\text{C} - 65^\circ\text{C}\) to allow primers to bind (anneal) to the complementary sequences on the single-stranded DNA.
3. Extension: The temperature is raised to around \(72^\circ\text{C}\), and Taq DNA polymerase adds nucleotides to the primers, extending the DNA and synthesizing new strands.

Cycle Repetition: These steps are repeated for 25–35 cycles, exponentially increasing the quantity of the target DNA.