Biotechnology: Principles and Processes — BIOLOGY STD 12 Science — Question

rDNA is the DNA formed by combining DNAs from two different organisms. In bacterial cell, rDNA can be transferred by using a vector where it multiplies into many copies. These copies are preserved as gene library.
Recombinant DNA technology involves the following steps:

1. Isolation of DNA.
2. Fragmentation of DNA by restriction endonucleases.
3. Isolation of a desired DNA fragment.
4. Amplification of the gene of interest.
5. Ligation of the DNA fragment into a vector.
6. Insertion of recombinant DNA into the host.
7. Culturing the host cells on a suitable medium at a large scale.
8. Extraction of the desired gene product.
9. Downstream processing of the products as finished product, ready for marketing.