Question

The sequence of a complete PCR cycle involves:

i. Extension
ii . DNA Melting
iii. Primer Annealing
What is the correct order for the PCR cycle?

Answer 1

The correct order for the PCR cycle is denaturation, primer annealing, and extension. These steps are repeated in cycles, leading to exponential amplification of the target DNA sequence.

Step-by-step explanation:

The correct order for the Polymerase Chain Reaction (PCR) cycle is as follows:

1. Denaturation: This step involves heating the DNA to a high temperature, typically around 95°C, to separate the double-stranded DNA into two single strands.
2. Primer Annealing: In the annealing step, the temperature is lowered to around 50°C to allow the primers to bind to their complementary DNA sequences on the single-stranded templates.
3. Extension: Finally, the temperature is increased to around 72°C, which is the optimal temperature for Taq polymerase to synthesize new DNA strands, extending from the annealed primers.

This cycle is repeated multiple times, with each cycle essentially doubling the number of DNA molecules, resulting in exponential amplification of the target sequence.