about transduction and transfection

1. PRESENTED BY :- KIRAN
B.S.c. BIOTECH
4TH SEM
TRANSDUCTION
AND
TRANSFECTION

2. TRANSDUCTION
 Transduction is the process by which DNA is
transferred from one bacterium to another by a
virus.
 It also refers to the process whereby foreign DNA is
introduced into another cell via a viral vector.
 Transduction does not require physical contact
between the cell donating the DNA and the cell
receiving the DNA (which occurs in conjugation),
and it is DNase resistant.
 Transduction is a common tool used by molecular
biologists to stably introduce a foreign gene into a
host cell's genome.

4. LYTIC AND LYSOGENIC (TEMPERATE) CYCLES
 Transduction happens through either the lytic cycle
or the lysogenic cycle.
 If the lysogenic cycle is adopted, the phage
chromosome is integrated (by covalent bonds) into
the bacterial chromosome, where it can remain
dormant for thousands of generations.
 If the lysogen is induced (by UV light for example),
the phage genome is excised from the bacterial
chromosome and initiates the lytic cycle, which
culminates in lysis of the cell and the release of
phage particles.
 The lytic cycle leads to the production of new
phage particles which are released by lysis of the
host.

5. LYTIC AND LYSOGENIC CYCLE IN LAMBDA PHAGE

6. Generalized transduction :-
 Generalized transduction is the process by which
any bacterial gene may be transferred to another
bacterium via a bacteriophage, and typically carries
only bacterial DNA and no viral DNA. In essence,
this is the packaging of bacterial DNA into a viral
envelope.
Specialized transduction:-
 Specialized transduction is the process by which a
restricted set of bacterial genes is transferred to
another bacterium.
 The genes that get transferred (donor genes)
depend on where the phage genome is located on
the chromosome.

7. MEDICAL APPLICATIONS
 Resistance to anti-biotic drugs
 Correcting genetic diseases by direct modification
of genetic errors

8. TRANSFECTION
 Transfection is the process of
deliberately introducing
nucleic acids into cells.
 Transfection of animal cells
typically involves opening
transient pores or "holes" in
the cell membrane to allow
the uptake of material.
 It involves the use of physical
and chemical methods to
persuade cells to take up
DNA into the cells.
 There are different transfer
methods like chemical
transfection, liposome
mediated transfection ,
lipofection , electroporation.
 The direct physical
introduction of DNA into the
cells involves microinjection
and particle bombardment.

9. LIPOFECTION
 Lipofection (or liposome
transfection) is a technique
used to inject genetic material
into a cell by means of
liposomes, which are vesicles
that can easily merge with the
cell membrane since they are
both made of a phospholipid
bilayer.
 Lipofection generally uses a
positively charged (cationic)
lipid to form an aggregate with
the negatively charged
(anionic) genetic material.
 A net positive charge on this
aggregate has been assumed
to increase the effectiveness of
transfection through the
negatively charged
phospholipid bilayer.
 The uptake of DNA through the
process of endocytosis.

10. ELECTROPORATION
 Electroporation is a
microbiology
technique in which
an electrical field is
applied to cells in
order to increase the
permeability of the
cell membrane, by
inducing the
formation of pores
within a membrane
and allowing
chemicals, drugs, or
DNA to be
introduced into the
cell.

11. PARTICLE BOMBARTMENT
 Also known as
microprojectile or
biolistic method.
 It employs foreign
DNA coated with
high velocity gold
or tungsten
particles to
deliver DNA into
target cells.

12. THANKYOU