Question

Main steps in the formation of Recombinant DNA are given below. Arrange these steps in a correct sequence.
A. Insertion of recombinant DNA into the host cell
B. Cutting of DNA at specific location by restriction enzyme
C. Isolation of desired DNA fragment
D. Amplification of gene of interest using PCR
Choose the correct answer from the options given below:

• A. C, A, B, D
• B. C, B, D, A
• C. B, D, A, C
• D. B, C, D, A

Answer 1

The Correct Option is B

To arrange the steps in the formation of Recombinant DNA in the correct sequence, let's understand each step and arrange them accordingly:

1. Isolation of desired DNA fragment (C):
   • The process begins with the isolation of the DNA fragment that contains the gene of interest from the donor organism. This is a critical step as it involves selecting the correct gene that needs to be cloned.
2. Cutting of DNA at specific location by restriction enzyme (B):
   • The isolated DNA fragment and the vector DNA are cut using the same restriction enzyme to generate compatible ends. This allows the desired fragment to be inserted into the vector DNA plasmid.
3. Amplification of gene of interest using PCR (D):
   • After the target DNA fragment has been cut, it can be amplified using Polymerase Chain Reaction (PCR) to make multiple copies of the gene of interest. Amplification ensures there is enough DNA to work with for further steps.
4. Insertion of recombinant DNA into the host cell (A):
   • The recombinant DNA (vector DNA with the inserted gene) is introduced into a host cell (often a bacterial cell), where it can be replicated and can express the desired protein encoded by the gene of interest.

Based on this logical flow, the correct sequence of steps is: C, B, D, A. This matches option two in the provided alternatives.