Revision: Biotechnology >> Biotechnology - Principles and Processes Biology Science (English Medium) Class 12 CBSE

The technique of bringing about improvements in living organisms by genetic modifications and hybridization, for the welfare of human beings is known as ‘Biotechnology’.

The European Federation of Biotechnology (EFB) defined biotechnology as ‘the integration of natural science and organisms, cells, parts thereof, and molecular analogues for products and services.’

• Biotechnology involves the use of biological systems, cells, and biomolecules along with genetic and non-genetic techniques for human welfare.
• It integrates sciences such as cytology, biochemistry, molecular biology, and genetic engineering and has major applications in agriculture and pharmacy.
• Biotechnology enables production of antibiotics, vaccines, hormones (insulin), antibodies, and development of high-yield crop varieties through tissue culture and gene manipulation.
• Major benefits include increased crop yield, development of disease- and stress-resistant varieties, and reduced expenditure on disease control.
• In India, biotechnology is promoted by the Department of Biotechnology (DBT) established in 1986, under which several national research institutes function.

1. Isolation of DNA:
   Genetic material (DNA) is extracted and purified from the source organism by removing proteins, RNA, lipids, and other impurities.
2. Cutting and Separation of DNA:
   DNA is cut at specific sites using restriction endonucleases, and desired fragments are separated by gel electrophoresis and isolated by elution.
3. Amplification of Gene (PCR):
   The gene of interest is amplified using Polymerase Chain Reaction (PCR) to produce millions of copies for effective cloning.
4. Ligation and Gene Transfer:
   The desired DNA fragment is ligated into a vector and introduced into a host cell by methods such as transformation, electroporation, or gene gun.
5. Expression and Production:
   The host cells expressing the recombinant gene are cultured on a large scale in bioreactors to produce the desired recombinant protein.
6. Downstream Processing:
   The final product is separated, purified, and processed to obtain a market-ready product.

• Biotechnology is based mainly on genetic engineering and bioprocess engineering.
• Genetic engineering involves altering DNA/RNA and introducing desired genes into a host to change its phenotype.
• Bioprocess engineering ensures sterile conditions for large-scale growth of desired microbes or cells to produce products like antibiotics and vaccines.
• Recombinant DNA technology allows transfer of only specific desirable genes, avoiding unwanted genes common in traditional breeding.
• For replication, an alien DNA must be linked to an origin of replication, enabling cloning inside the host.
• Genetic modification involves three steps: identifying the desired gene, introducing it into the host, and maintaining and inheriting it in progeny.

• Cloning vectors are DNA molecules (plasmids or bacteriophages) that can replicate independently inside host cells and help multiply foreign DNA.
• An origin of replication (ori) is essential for replication of the vector and controls the copy number of the inserted DNA.
• Selectable marker genes (e.g., antibiotic resistance genes) help identify and select transformed cells from non-transformants.
• Cloning sites are unique restriction enzyme recognition sites where foreign DNA is inserted into the vector.
• Insertional inactivation of marker genes (e.g., β-galactosidase) helps distinguish recombinants from non-recombinants using colour screening.
• Special vectors like Ti plasmid of Agrobacterium tumifaciens and modified retroviruses are used to transfer genes into plant and animal cells.