Arrange the following processes of recombinant DNA technology in a correct sequence:

(A). Amplification of gene by using PCR

(B). Isolation of DNA and cutting of DNA at specific location

(C). Obtaining the desired foreign gene product

(D). Insertion of recombinant DNA into the host

Choose the correct answer from the options given below:

(B), (A), (D), (C)

The correct answer is Option (3) → (B), (A), (D), (C)

(B). Isolation of DNA and cutting of DNA at specific location

(A). Amplification of gene by using PCR

(D). Insertion of recombinant DNA into the host

(C). Obtaining the desired foreign gene product

In recombinant DNA (rDNA) technology, the steps occur in a specific sequence to ensure that the desired genetic material is accurately isolated, modified, and introduced into a host cell. Here’s an explanation of each step in the correct order:

1. Isolation of the genetic material : The process begins by extracting the DNA containing the gene of interest from a cell. This is often done by breaking open the cells and using techniques to separate the DNA from other cellular materials.
2. Cutting the DNA at specific locations: Once isolated, the DNA is cut at specific points using restriction enzymes. After having cut the source DNA as well as the vector DNA with a specific restriction enzyme, the cut out ‘gene of interest’ from the source DNA and the cut vector with space are mixed and ligase is added. This results in the preparation of recombinant DNA.
3. Amplification of gene by PCR : After cutting, the gene of interest is amplified using PCR (Polymerase Chain Reaction). This technique makes multiple copies of the gene, ensuring there is enough DNA available for the next steps in the rDNA process.
4. Insertion of rDNA into host cell using vector: After the DNA fragment is ligated into the vector, the recombinant DNA is ready for transfer into the host organism, such as bacteria, plant cells, or animal cells. This transfer is usually achieved through transformation methods specific to the host organism, such as electroporation or biolistics.
5. Obtaining the foreign gene product – Once the recombinant DNA is successfully transferred into the host, the host cells begin to produce the desired gene product, such as a protein or enzyme encoded by the gene of interest. The gene product is then extracted and purified for various applications, such as medical treatments, biotechnology, or research.

By following these steps, scientists can manipulate DNA to introduce specific genes into different organisms, leading to the production of desired gene products with various applications in medicine, agriculture, and industry.