Which of the following is the first and the most important step in the polymerase chain reaction?

 

Question:  Which of the following is the first and the most important step in the polymerase chain reaction?

A   Annealing

B   Primer extension

C   Denaturation

D   None of the above

Answer:  Denaturation

 

Steps involved in PCR                      Description
Denaturation ·        Heating of the DNA sample to a high temperature usually around 94-98°C.

·        This process separates the double-stranded DNA into two single strands and provides a template for amplification.

Annealing ·        Annealing involves lowering of the temperature typically around 50-65°C.

·        This allows primers to bind to the single-stranded DNA template.

·        Primer sequences are specific to the target DNA.

Extension ·        Extension includes raising the temperature upto 72°C.

·        DNA polymerase extends the primers by adding nucleotides, synthesizing a complementary strand.

·        The enzyme builds a new DNA strand from the template.

·        The target DNA is amplified in this step.