Name: Genetic Engineering in Health
Uploaded: 2019-07-19
Duration: 5 min 10 s
Description: Genetic Engineering holds the key to the door of wide possibilities. Watch this video to learn how genes are being edited and stitched and how they impact humanity and life!

Question

Identify and explain steps 'A', 'B' and 'C' in the PCR diagram given below.

Accepted Answer

Polymerase Chain Reaction is a technique that is used to amplify and synthesise multiple copies of the desired gene in vitro within a short time. In this process, the two strands of DNA are separated using high temperature. These strands are then copied using a DNA polymerase which is then repeated many times to obtain multiple copies.

Amplification of a gene of interest is carried out using PCR in the following three steps:
1. Denaturation: The double-stranded DNA is denatured by applying a high temperature of about 94-96⁰C for 15 seconds. Each separated strands of DNA now acts as a template for the synthesis of a new DNA strand.

2. Annealing: Two sets of primers are added which anneal at the 3’ end of each separated strand. These mark the beginning of replication.

3. Extension: A thermostable DNA polymerase (Taq polymerase) obtained from the bacteria Thermus aquaticus, extends the primers by adding nucleotides, complementary to the template provided in the reaction. The cycle of denaturation, annealing and extension is repeated several times to obtain several copies of desired DNA.

Thus, the given steps marked as A, B and C represent the denaturation, annealing and extension of DNA, respectively.

Identify and explain steps 'A', 'B' and 'C' in the PCR diagram given below.

Important Questions on Biotechnology: Principles and Processes

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