This document introduces the polymerase chain reaction (PCR) technique. It explains that PCR is used to amplify a small segment of DNA across many orders of magnitude, generating thousands to millions of copies of a particular sequence. The principle of PCR involves denaturing DNA, annealing primers to the DNA, and extending the DNA via polymerase. Key instrumentation is used to perform PCR. The document concludes that PCR has significant forensic applications like identifying human remains and developing genetic fingerprints from crime scene samples.

2. Introduction of PCR
technique
Presented by
Teena Lodhi
Volunteer
Applied Forensic Research
Sciences

3. Content
 Introduction of PCR
 Principle of PCR
 Instrumentation of PCR
 Conclusion
 Forensic Significance
 Refrances

4. INTRODUCTION TO
PCR TECHNIQUE
PCR- Polymerase chain reaction
 PCR is technique a used in molecular
biology to amplify a single copy or a
few copies of a segment of DNA
across several orders of magnitude,
generating thousands to millions of
copies of a particular DNA sequence.
 PCR is a technique that takes specific
sequence of DNA of small amount
and amplifies it to be used for further
testing.

5. Principle of PCR
 To amplify a lot of double-
stranded DNA molecules
fragments) with same
(identical) size and
sequence benzymatic
method and cycling
condition.
 The DNA amplification is
detected in real-time with
the help of a fluorescent

6. Denaturation :-temperature: 92-94C
Double stranded DNA melts single stranded
DNA

7. Annealing
Temperature: ~50-70C (dependant on the melting
temperature of the expected duplex) Primers bind
to their complementary sequences

8. Extension:-
Temperature: ~72C
Time: 0.5-3min
DNA polymerase binds to the annealed primers and
extends DNA at the 3' end of the chain

9. Overall Principle of PCR
DNA-1 copy
Known sequence Sequence of interest known
sequence
PCR

10. Instrumentation

11. Conclusion
 PCR is not only vital in
the clinical laboratory
by amplifying small
amounts of DNA for
STD detection .
 The PCR technology
can also be employed
in law enforcement,
genetic testing of
animal stocks and
vegetable hybrids, and
drug screening along

12. Forensic Significance
of PCR
 Polymerase chain reaction (PCR) is currently
the method of choice for the identification of
human remains in forensic coursework.
 DNA samples from crime scenes often contain
co-purified impurities which inhibit PCR.
 PCR can be used as a tool in genetic
fingerprinting.
 it possible to develop forensic genetics tools
that allow both very informative routine
investigations and still more and more
advanced, special investigations in cases
concerning crime, paternity, relationship,

13. Refrances
https://www.slideshare.net/AYSHA007/copy-of-
pcr
EG pathshala.
https://www.slideshare.net/FarazaJaved/pcr-
76618045
https://pubmed.ncbi.nlm.nih.gov/21917539/#:~:t
ext=Polymerase%20chain%20reaction%20(PCR)%2
0is,copies%20of%20DNA%20are%20present.

14. Thank you