BIOTECH 1

 

INTRODUCTION

• Biotechnology deals with the techniques of using living organisms or enzymes from organisms to produce products useful to humans.

• The processes like in vitro fertilization leading to a ‘test-tube’ baby, synthesizing a gene and using it, developing a DNA vaccine or correcting a defective gene, are all parts of biotechnology.

• Biotechnology can be defined as- ‘The integration of natural science and organisms, cells, parts there of, and molecular analogues for products and services’.

PRINCIPLES OF BIOTECHNOLOGY

The two core techniques that enabled birth of modern biotechnology are –

1. Genetic engineering

2. Maintenance of sterile conditions.

 

• Genetic engineering is the technique of altering the chemistry of DNA and RNA so that it can be introduced into the host organism to change the phenotype of the host organism.
• Sterile conditions should be maintained to enable growth of only the desired microbe or eukaryotic cell in large quantities for the manufacture antibiotics, vaccines, enzymes, etc.

Why we need genetic engineering??

• Hybridization (sexual reproduction)  procedures often lead to inclusion and multiplication of undesirable genes along with the desired genes.

• The techniques of genetic engineering which include creation of recombinant DNA, use of gene cloning and gene transfer allows us to isolate and introduce only one or a set of desirable genes without introducing undesirable genes into the target organism.

Problem - an isolated piece of DNA (containing desired gene) would not be able to reproduce itself in the progeny cells..

Solution - when it is integrated in the genome of recipient cells- multiply along with host DNA.

Three basic steps in genetically modifying an organism —

• Identification of DNA with desirable genes
• Introduction of the identified DNA into the host
• Maintenance of introduced DNA in the host and transfer of the DNA to its progeny.

TOOLS OF RECOMBINANT DNA TECHNOLOGY

Important tools of recombinant DNA technology are-

• Restriction enzymes- Restriction enzymes are called as molecular scissors because these enzymes cut DNA at specific sites.
• Cloning vector- Plasmids and bacteriophages have the ability to replicate within bacterial cells independent of the control of chromosomal DNA.
• Competent host- The host should be competent enough to take up the foreign DNA.
• Bioreactors- Bioreactor is the cylindrical vessel in which biological processes is carried out on a large scale.