3. The definition
• The definition. PCR is a technique used
to amplify and replicate ribonucleic acid
(RNA) or deoxyribonucleic acid (DNA) in
a small sample using the polymerase
chain reaction enzyme, nucleotides, and
primers. These components work
together to sequentially replicate a
specific DNA sequence.
Historical overview
• In 1971, the Cetus Corporation, a biotechnology company, was founded.
This company would become the primary site for most of the research
leading to the invention of the polymerase chain reaction (PCR) in 1983. PCR
was invented by Kary Mullis at the Cetus Corporation. In 1984, Mullis and
the genetic mutation screening team at Cetus began conducting
experiments demonstrating the ability of PCR to amplify genomic DNA.
They also used PCR to determine the amount of HIV in blood samples in the
spring of 1985, they applied for a patent on PCR and its applications, which
was approved in 1987. By mid-1987, a viable test had been developed using
this interaction.
4. PCR technique Benefits
02
02 Accuracy of results
01
01 Speed of analysis
03 Disease diagnosis
03
04 Drug development
04
05 Genetic evolution studies
05
06 Forensic applications
06
5. Accuracy of results
PCR technology allows for repeated
analysis, increasing the accuracy of
results and reducing the likelihood
of errors.
02
Speed of analysis
PCR technology allows for rapid and efficient
amplification of DNA, enabling analysis of a
small DNA sample in a short amount of time
01
6. 03
Disease diagnosis
PCR technology can be used in
diagnosing various diseases such as
infectious, genetic, and cancerous
diseases.
04
Drug development
PCR technology can be used in testing
the effectiveness of drugs and
developing new treatments for
various diseases.
7. Genetic evolution studies
PCR technology can be used in studying
genetic evolution and identifying genetic
differences between different species
05 06
Forensic applications
PCR technology can be used in
forensic investigations to determine
the identity of suspects and verify
their genetic traces at the crime scene.
8. PCR in different fields
environmental science Agriculture Forensic science Medicine
9. It is also used in environmental
science for monitoring
biodiversity, studying microbial
communities, and detecting
environmental
environmental science
10. PCR technology is used for
genetic testing of crops and
livestock to improve breeding
programs and ensure food safety.
Agriculture
11. PCR technology is used for DNA
profiling and identifying suspects in
criminal investigations. It has been
instrumental in solving cold cases
and exonerating wrongly accused
individuals.
Forensic science
12. PCR technology is widely used for
disease diagnosis, including infectious
diseases such as HIV , as well as genetic
diseases like cystic fibrosis and sickle
cell anaemia. It is also used in cancer
research to detect specific genetic
mutations and in pharmacogenomics
to personalize drug treatments based
on an individual's genetic profile.
Medicine
13. Types of samples used in PCR
Blood Environmental Forensic Saliva Tissue
Forensic
14. The amplification
of gene
fragments
The sensitive
detection of
pathogenic
microorganisms
The detection of
mutations
The analysis of
genetic markers
The modification
of DNA fragments
The study of gene
expression
applications of PCR
DNA analysis
15. Thermal cycler Process
The thermal cycler process is a heating and cooling it involves three phases :-
•denaturing
The temperature is raised from 94 to 98 C , which leads to the separation of DNA
strand
•annealing
The temperature is reduced between 45 and 60 to allow primers to bind to the
complementary sequence on each of the DNA single strands
•extending
temperature increase to 72 This final increased allows the Taq polymerase
enzyme to replicate the template DNA
Results
the results appear on gel electrophoresis
Positive PCR Result
A positive PCR result is indicated by the presence of
a band on the gel that corresponds to the expected
size of the PCR product.
Negative PCR Result
A negative PCR result is indicated by the absence of
a band on the gel that corresponds to the expected
size of the PCR product.
16. Process
In RT PCR, the number of PCR cycles is shown on the x-axis, and the fluorescence from
the amplification reaction, which is proportional to the amount of amplified product in
the tube, is shown on the y-axis.
The amplification plot shows two phases: the exponential phase, During this phase,
the amount of PCR product doubles in each cycle as the reaction proceeds, however,
reaction components are consumed, and ultimately the components become limiting
at this point, the reaction slows and enters the plateau phase (cycles 28–40)
Real-time PCR
(RT-PCR)
Results
The interpretation of RT-PCR results is based on the cycle threshold (Ct) value.
Positive RT-PCR Result
A positive RT-PCR result is indicated by a Ct value within the expected range for
the target DNA sequence. .
Negative RT-PCR Result
A negative RT-PCR result is indicated by a Ct value
that is either absent or outside the expected range
for the target DNA sequence.
17. OUR TEAM
Assem Khalid
Ahmed Farahat
Osama Hamdy Fathy
Menna Khalid
Shahd Mostafa Shaban
Shahd Ahmed Akl
Hager Ahmed Ragab
Aya Mohamed Sayed
Manar Mahmoud
Nada Reda
Nourhan gaber ahmed
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