Biotechnology:Principles and Processes
Biotechnology deals with techniques of using live organisms or enzymes from organisms to produce products and processes for human welfare.
Modern biotechnology use genetically modified organisms generated by the process of recombinant DNA technology.
The first step in the recombinant technology is the isolation and purification of the desired DNA. This DNA is then fragmented with restriction endonucleases.
These enzymes cut both strands of a DNA molecule at specific recognition site. They may produce either blunt end or staggered end in a DNA molecule.
The fragments of DNA are then separated by gel electrophoresis.The DNA fragments are visualised on the gel by using ethidium bromide.
Southern blotting is a hybridisation technique used to identify a known DNA sequence in the given sample.
The vector is cut with the same restriction enzyme that is used to cut target DNA. The target gene is joined to the vector with the help of the DNA ligase to form a recombinant DNA molecule. The recombinant DNA molecules may be amplified billion times by the Polymerase Chain Reaction.
The recombinant DNA is then introduced into a suitable host which becomes “transformed”. The methods of introduction are transformation, transfection, electroporation, chemical method, microinjection and gene gun.
Next the transformed hosts are selected with the help of genetic markers like. Antibiotic-resistant genes, present in the vector.
The gene product yielded in the recombinant cell is extracted and purified. Recombinant protein can be produced on a small scale, under laboratory conditions, inside the prokaryotic cells.
Large scale production is done in bioreactors