Which of the following is not a step of Polymerase Chain Reaction?

Downstream processing

The correct answer is Option (2) → Downstream processing

Downstream processing is not a step in PCR. It refers to the purification and preparation of final products in biotechnology processes after PCR amplification or production is complete. As PCR cycles progress, the number of copies of the target DNA sequence doubles with each cycle, leading to a significant increase in the amount of DNA. This accumulation of DNA copies is what we refer to as "amplified DNA."

In Polymerase Chain Reaction (PCR), the main steps involved are:

1. Denaturation: Heating the DNA to separate it into single strands.
2. Annealing: Cooling the reaction so primers can bind to the single-stranded DNA.
3. Extension: DNA polymerase extends the primers to synthesize new DNA strands.

Polymerase chain reaction (PCR) : Each cycle has three steps: (i) Denaturation; (ii) Primer annealing; and (iii) Extension of primers