Question

Explain various steps involved in rDNA technique.

Answer 1

rDNA technique joins a foreign gene to a vector and expresses it in a host.

Steps:

1. Isolation of DNA by breaking cells and removing RNA, proteins and other molecules.
2. Cutting of DNA and plasmid with the same restriction endonuclease.
3. Amplification of the desired gene by cloning or PCR.
4. Formation of rDNA by joining the gene to the plasmid with DNA ligase.
5. Insertion of rDNA into the host cell by competent or direct methods, with screening by selectable marker.
6. Obtaining the product by culturing host cells in bioreactors and purifying the protein.

These steps together produce useful proteins such as insulin on a large scale.