• Biotechnology is a field that involves harnessing biological systems and organisms like bacteria, yeast, and plants to perform specific tasks or produce valuable substances.
  • It is based on basic biological sciences such as molecular biology, biochemistry, and genetics, providing methods to support research in biology.
  • The term "biotechnology" was first used in 1919 by Károly Ereky to refer to the production of products from raw materials with biological aid.
  • Biotechnology encompasses procedures for modifying living organisms for human purposes, including genetic engineering, cell culture, and tissue technologies.
  • The European Federation of Biotechnology (EFB) has defined biotechnology as including both traditional and modern molecular biotechnology.The term is defined as follows: "The integration of natural science and organisms, cells, parts thereof, and molecular analogous for products and services".


Principles of Biotechnology


  • The principles of biotechnology are based on the manipulation of living organisms or their components to produce useful products for human welfare. 
  • The two core techniques that enabled the birth of modern biotechnology are genetic engineering and bioprocess engineering.
  • Genetic Engineering -This principle involves the modification of the DNA of a target organism, thereby changing its phenotype. It is used to introduce new genes or correct defective ones in living organisms.
  • Bioprocess Engineering - The maintenance of sterile ambience in chemical engineering processes to enable the growth of only the desired microbe or eukaryotic cell in large quantities for the manufacture of biotechnological products like antibiotics, vaccines, enzymes, etc.
  • The conceptual development of the principles of genetic engineering involves manipulating and modifying the genetic material of an organism to incorporate desirable traits. This process includes techniques like the creation of recombinant DNA, gene cloning, and gene transfer to overcome limitations seen in traditional hybridization methods.
  • Genetic engineering allows for the isolation and introduction of specific desirable genes without introducing undesirable ones. When a piece of DNA is transferred into an alien organism, it may not multiply in progeny cells initially, but if integrated into the recipient's genome, it can replicate and be inherited.
  • Alien DNA must be part of a chromosome to multiply in a cell. The chromosome has a segment known as the 'origin of replication'. This initiates chromosomal replication. When alien DNA is incorporated into the origin of replication, it can replicate in the host cell. This process is known as cloning or making multiple identical copies of the DNA template.
  • This field has evolved over time, with advancements like the creation of transgenic organisms and the development of genetically modified organisms (GMOs) for various applications in research, medicine, industrial biotechnology, and agriculture.


First instance of the construction of Artificial Recombinant DNA 


  • The first instance of the construction of artificial recombinant DNA molecule was achieved using the bacterium Salmonella typhimurium. This was due to the possibility of linking a gene encoding antibiotic resistance with a native plasmid (autonomously replicating circular extra-chromosomal DNA) of the bacterium. 
  • This groundbreaking work was carried out by scientists like Stanley Cohen and Herbert Boyer in 1972. They took the resistance plasmid from Salmonella typhimurium, isolated it, and treated it with a restriction endonuclease which cut the resistance gene. The cutting of DNA at specific locations became possible with the discovery of the so-called ‘molecular scissors’– restriction enzymes
  • Plasmids helped in transferring the required DNA from the source to the host cell, molecular scissors cut the DNA at the desired position, and DNA ligase joined the created DNA fragments into one single plasmid.
  • This was then transferred using vectors in the host cell, which in this case was E.coli. The newly formed circular recombinant DNA was transferred to E.coli and replicated in the host cell.
  • The transformed cells were then isolated using the marker on the transferred gene. This marked the beginning of the era of genetic engineering and recombinant DNA technology.


The basic steps of  Recombinant DNA Technology can be summarised as:

(i) Identification of DNA with desirable genes.
(ii) Introduction of the identified DNA into the host.
(iii) Maintenance of introduced DNA in the host hrtd transfer of the DNA to its progeny.