Module 6: Polymerase chain reaction Flashcards
(10 cards)
PCR is a method for …
make a further point about what PCR is
amplifying DNA fragments rapidly and efficiently
-its an automated technique that doesn’t require living cells in order to replicate specific DNA fragments
Give the 5 components needed for PCR
a DNA fragment
primers
free nucleotides
DNA polymerase
a thermocycler
What are primers?
short sequences of nucleotides that attach to the start and end of the DNA fragment to be copied
What does the thermocycler do in PCR?
its a device that precisely heats and cools the PCR mixture to facilitate the reaction
Name the specific type of DNA polymerase used in PCR and why this one is used
Taq polymerase
-its derived from a thermophilic bacteria so can withstand the high temperatures required for PCR without denaturing
Name the 3 processes involved in each PCR cycle
-give the temperature required for each stage
1) Separation (95 degrees)
2)Addition of primers/ annealment (55 degrees)
3)DNA synthesis (72 degrees)
Make 1 point about the separation stage of PCR
the solution is heated to separate the hydrogen bonds between the 2 complementary DNA strands
Make 1 point about the annealment stage of PCR
the primers attach to specific starting points on each of the DNA strands by forming hydrogen bonds
Make 1 point about the DNA synthesis stage of PCR
DNA polymerase adds free nucleotides to the ends of the primers to form a new complete copy of the DNA strand
Give the 4 key advantages of the PCR technique
-make an explanation point for each (not the last one)
rapid speed-it can produce approx 100 million copies in a few hours which is not possible in in-vivo cloning
precised-automated nature of thermocycling ensures accurate amplification of the DNA fragment
low DNA needs-only requires tiny samples to produce a large number of copies
no cells needed
