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GENETIC ENGINEERING
Genetic engineering primarily involves the manipulation of genetic material (DNA) to achieve
the desired goal in a pre-determined way. Some other terms are also in common use to describe
genetic engineering.
Gene manipulation
Recombinant DNA (rDNA) technology
Gene cloning (molecular cloning)
Genetic modifications
New genetics
A clone is an identical copy. This term originally applied to cells of a single type, isolated and
allowed to reproduce to create a population of identical cells. DNA cloning involves separating a
specific gene or DNA segment from a larger chromosome, attaching it to a small molecule of
carrier DNA, and then replicating this modified DNA thousands or millions of times through
both an increase in cell number and the creation of multiple copies of the cloned DNA in each
cell. The result is selective amplification of a particular gene or DNA segment.
MOLECULAR CLONING
The basic procedure of molecular cloning involves a series of steps.
1. Cutting DNA at precise locations. Sequence-specific endonucleases (restriction
endonucleases) provide the necessary molecular scissors.
2. Selecting a small molecule of DNA capable of self-replication. These DNAs are called
cloning vectors (a vector is a delivery agent). They are typically plasmids or viral DNAs.
3. Joining two DNA fragments covalently. The enzyme DNA ligase links the cloning vector
and DNA to be cloned. Composite DNA molecules comprising covalently linked
segments from two or more sources are called recombinant DNAs.
4. Moving recombinant DNA from the test tube to a host cell that will provide the enzymatic
machinery for DNA replication.
5. Selecting or identifying host cells that contain recombinant DNA.
The methods used to accomplish these and related tasks are collectively referred to as
recombinant DNA technology or, more informally, genetic engineering.
CLONING VECTORS
Cloning vectors are carrier DNA molecules. Four important features of all cloning vectors are
that they: (i) can independently replicate themselves and the foreign DNA segments they carry;
(ii) contain a number of unique restriction endonuclease cleavage sites that are present only once
in the vector; (iii) carry a selectable marker (usually in the form of antibiotic resistance genes or
genes for enzymes missing in the host cell) to distinguish host cells that carry vectors from host
cells that do not contain a vector; and (iv) are relatively easy to recover from the host cell. There
Pdf Download Link At End
GENETIC ENGINEERING
Genetic engineering primarily involves the manipulation of genetic material (DNA) to achieve
the desired goal in a pre-determined way. Some other terms are also in common use to describe
genetic engineering.
Gene manipulation
Recombinant DNA (rDNA) technology
Gene cloning (molecular cloning)
Genetic modifications
New genetics
A clone is an identical copy. This term originally applied to cells of a single type, isolated and
allowed to reproduce to create a population of identical cells. DNA cloning involves separating a
specific gene or DNA segment from a larger chromosome, attaching it to a small molecule of
carrier DNA, and then replicating this modified DNA thousands or millions of times through
both an increase in cell number and the creation of multiple copies of the cloned DNA in each
cell. The result is selective amplification of a particular gene or DNA segment.
MOLECULAR CLONING
The basic procedure of molecular cloning involves a series of steps.
1. Cutting DNA at precise locations. Sequence-specific endonucleases (restriction
endonucleases) provide the necessary molecular scissors.
2. Selecting a small molecule of DNA capable of self-replication. These DNAs are called
cloning vectors (a vector is a delivery agent). They are typically plasmids or viral DNAs.
3. Joining two DNA fragments covalently. The enzyme DNA ligase links the cloning vector
and DNA to be cloned. Composite DNA molecules comprising covalently linked
segments from two or more sources are called recombinant DNAs.
4. Moving recombinant DNA from the test tube to a host cell that will provide the enzymatic
machinery for DNA replication.
5. Selecting or identifying host cells that contain recombinant DNA.
The methods used to accomplish these and related tasks are collectively referred to as
recombinant DNA technology or, more informally, genetic engineering.
CLONING VECTORS
Cloning vectors are carrier DNA molecules. Four important features of all cloning vectors are
that they: (i) can independently replicate themselves and the foreign DNA segments they carry;
(ii) contain a number of unique restriction endonuclease cleavage sites that are present only once
in the vector; (iii) carry a selectable marker (usually in the form of antibiotic resistance genes or
genes for enzymes missing in the host cell) to distinguish host cells that carry vectors from host
cells that do not contain a vector; and (iv) are relatively easy to recover from the host cell. There
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