1. POLYMERASE
CHAIN REACTION
(PCR)
BY: Rachel Randall
"PCR is the most important new
scientific technology to come along
in the last hundred years,"
says Mark R. Hughes, deputy
director of the Human Genome
Project

2. PCR
 PCR is a method of heating and cooling of a small amount of
DNA to make copies for further testing
 Billions of copies can be made in a matter of hours with each
cycle taking 1-3 minutes
 The DNA template can undergo at least 30-40 cycles always
doubling in quantity
 An automated Thermo Cycler that can heat and cool the reaction
tubes in a short amount of time

3. CREATION
 Invented by Kary Mullis in 1993
 He received a Nobel Prize and Japan Prize for his new innovative method
 He was developing it for 10 years since its conception in 1983
 Created on of the most monumental scientific techniques of the
20th century

4. WHAT’S INVOLVED
 The small DNA template strand to be amplified
 DNA nucleotides
 Two Primers, single-stranded DNAs between 20 and 50
nucleotides long (oligonucleotides)
 complementary to a short region on either side of the template DNA
 Heat-resistant Taq polymerase that speeds up the process

5. STEP ONE: DENATURING
 break apart the DNA strand by heating to about 94 degrees
Celsius
 This gives access to the rungs that contains the nucleotide bases
 Stops all enzymatic reactions (the extension from a previous
cycle).

6. STEP TWO: ANNEALING
 allowing two sequences of DNA to form hydrogen bonds
 annealing of the target sequences and primers is done by cooling
the DNA to 55°C
 If the primers exactly fit the template, the hydrogen bonds are so
strong that the primer stays attached

7. STEP THREE: EXTENSION
 Raise to body temperature or 72 degrees Celsius
 Winds DNA strands back together
 Makes more of the needed copies of the template

8. CONTRIBUTIONS
 Quicker, simpler and more reliable results for more tests like…
 Gene Expression Analysis
 The diagnosis of an infectious disease
 Human genetic testing

9. FUTURE
 Smaller machines
 Cost
 Speed
 Amount able to copy

10. ETHICS
 Unethical since DNA is produced so quickly and easily, it might be
possible for outside sources to obtain a copy of it for their own use
without the owner's permission
 May prevent insurance companies from insuring a person if the
have a segment of their DNA that shows they have or carry the
genes for a fatal or deadly disease
 Also, some people think the genetic engineering is unethical
altogether, and believe that DNA should be left alone to replicate
naturally in the cell

14. BIOGRAPHY
 http://www.sciencedaily.com/releases/2011/04/110421104508.htm
 http://www.horizonpress.com/pcr/pdf/rtpcr/rtpcr01.pdf
 http://www.accessexcellence.org/RC/VL/GG/polymerase.php
 http://www.nhlcyberfamily.org/tests/pcr.htm