TOOLS OF GENETIC ENGINEERING-
BASIC REQUIREMENTS
Genetic engineering (= gene cloning, DNA
technology) can be de ned-as "changing of
genes by using in vitro processes". A gene of
known function can be transferred from its
normal location into a cell (that of course, does
not contain it) via a suitable vector. The
transferred gene replicates normally and is
handed over to the next progeny. On
con rmation for its presence through
biochemical procedures replica of the same
cell (i.e. clones) can be produced. The derivation
of procedures for the reintroduction of the
foreign DNA fragment into a bacterium
have lead to evolution of new technology, i.e. the
recombinant DNA technology, gene cloning,
gene manipulation or genetic engineering.
The macromolecules such as DNA, RNA,
proteins, etc. are synthesised inside the living
cells which vary with each other
in respect of molecular weight (size), solubility,
presence of charges, absorbance of light
fi fi
, wavelength (spectrum), etc. There are many
techniques that are used to isolate and
characterise the macromolecules on the basis of
di erentiating features.
Size of di erent types of molecules varies and,
therefore, their molecular weight also varies. For
example, a macromolecule of small size show
less molecular weight and vice versa.
Techniques-used on the basis of molecular
weight are: gel permeation, osmotic pressure,
polarity of charges.
A.GEL PERMEATION OR GEL
FILTRATION
In this technique polymeric organic compound is
used to prepare a porous medium. The polymers
form a three-dimensional network of pores. The
pore size is determined by degree of cross-
linking of polymeric chains. Solutes present in
the mixture are separated on the basis of their
size and shape when they pass through a
column consisting of packed gel particles . For
such separation many terms like exclusion
chromatography, gel ltration and molecular
ff
ff fi
BASIC REQUIREMENTS
Genetic engineering (= gene cloning, DNA
technology) can be de ned-as "changing of
genes by using in vitro processes". A gene of
known function can be transferred from its
normal location into a cell (that of course, does
not contain it) via a suitable vector. The
transferred gene replicates normally and is
handed over to the next progeny. On
con rmation for its presence through
biochemical procedures replica of the same
cell (i.e. clones) can be produced. The derivation
of procedures for the reintroduction of the
foreign DNA fragment into a bacterium
have lead to evolution of new technology, i.e. the
recombinant DNA technology, gene cloning,
gene manipulation or genetic engineering.
The macromolecules such as DNA, RNA,
proteins, etc. are synthesised inside the living
cells which vary with each other
in respect of molecular weight (size), solubility,
presence of charges, absorbance of light
fi fi
, wavelength (spectrum), etc. There are many
techniques that are used to isolate and
characterise the macromolecules on the basis of
di erentiating features.
Size of di erent types of molecules varies and,
therefore, their molecular weight also varies. For
example, a macromolecule of small size show
less molecular weight and vice versa.
Techniques-used on the basis of molecular
weight are: gel permeation, osmotic pressure,
polarity of charges.
A.GEL PERMEATION OR GEL
FILTRATION
In this technique polymeric organic compound is
used to prepare a porous medium. The polymers
form a three-dimensional network of pores. The
pore size is determined by degree of cross-
linking of polymeric chains. Solutes present in
the mixture are separated on the basis of their
size and shape when they pass through a
column consisting of packed gel particles . For
such separation many terms like exclusion
chromatography, gel ltration and molecular
ff
ff fi
