PCR (polymerase chain reaction) is a technique used to amplify specific DNA sequences. It involves repeated cycles of heating and cooling of the DNA sample to separate and copy the DNA strands. There are several types of PCR including nested PCR, which increases sensitivity by using two rounds of amplification, and multiplex PCR, which allows simultaneous amplification of multiple DNA sequences. PCR and its variations have widespread applications in medicine, forensics, agriculture, and research by enabling identification of organisms, understanding disease pathology, and selective isolation of DNA fragments.

1. PCR AND ITS TYPES

2. CONTENTS
• PCR Definition
• PCR history
• PCR procedure
• PCR types
• PCR applications
• Conclusion
• References

6. • POLYMERASE CHAIN
REACTION

7. Pcr

8. PCR STEPS

9. PCR STEPS

11. PCR STEPS

12. Cycling conditions for amplifying longer PCR products
Step Time/cycles Temperature
Initial activation step 2 min 95°C
3-step cycling
Denaturation 10 s 94°C
Annealing 1 min 50–68°C*
Extension 1 min/kb
Number of cycles 40 cycles 68°C
End of PCR cycling Indefinite 4°C

14. PCR

16. PCR TYPES

17. PCR TYPE

19. • Overlap-extension PCR or Splicing by overlap
extension (SOEing) :
• Genetic engineering technique
• used to splice together two or more DNA
fragments OR complementary sequences.
• It is the technique enables creation of
specific and long DNA constructs.
• It can also introduce deletions, insertions or
point mutations into a DNA sequence.

20. • Nested PCR
• This PCR increases the sensitivity
• Two sets of primers,
• A double process of amplification .
• The first set of primers allow a first
amplification. The product of this PCR is
subjected to a second PCR using the second
set of primers.
• Primers used in the second PCR are specific
to an internal amplified sequence in the first
PCR. specificity of the first PCR product is
verified with the second one.

22. • Semi quantitative PCR
• An approximation to the relative amount of
nucleic acids present in a sample,
• The markers commonly used are
• Apo A1 and B actin.
• Amplification product is separated by
electrophoresis

23. • Multiplex PCR
• Multiplex PCR is an adaptation of PCR which
allows simultaneous amplification of many
sequences.
• This technique is used for diagnosis of
different diseases
• Multiplex PCR can detect different pathogens
in a single sample.

24. PCR TYPES

25. Applications of PCR and impact on
science
• PCR and its different variations are highlighted
as the most commonly used in laboratories
and research institutes.
• Thus, these have contributed to identification
• characterization of several organisms and
understanding of physiopathology of diverse
• diseases in human, animal and plants.

26. • MEDICINE
• identification of microorganisms
assurance of blood
• Forensic
• As a basic procedure to investigate Deaths
• (paternity testing)
• Evidence from minimal samples of saliva,
semen or other tissue debris

27. AGRICULTURE
• As conventional PCR or qPCR have also
facilitated research in
• Detection of pathogens in plants, animals,
and the environment; understanding of their
• Epidemiology and, development of new
diagnostic tests, treatments or vaccines.

28. • Selective DNA isolation
• Isolation of DNA fragments from genomic DNA
by selective amplification of a specific region of
DNA.
• This use of PCR augments many methods, such as
generating hybridization Probes and DNA cloning
which require larger amounts of DNA,
representing a specific DNA region.
• PCR supplies these techniques with high
amounts of pure DNA, enabling analysis of DNA
samples Possible.