Polymerase Chain Reaction

Question 1

who devised PCR

Answer 1

Kary Mullis in 1980s

Question 2

what is the principle of PCR

Answer 2

an in vitro enzymatic method for amplifying exponentially a specific pre selected fragment of DNA

Question 3

what is needed for PCR

Answer 3

DNA source (template), DNA polymerase, primers, deoxyribonucleoside triphosphates

Question 4

what are the three steps of PCR

Answer 4

denaturation, annealing, extension

Question 5

what is denaturing

Answer 5

hydrogen bonds are broken by high heat.

Question 6

what is annealing

Answer 6

primers anneal to separate sites on opposite template strands

Question 7

what is extension

Answer 7

extension of the primers by polymerase mediated nucleotide additions to produce copies of the DNA sequence

Question 8

what function has Taq polymerase

Answer 8

thermal resistant. reduces non specific binding as it can survive at high temps

Question 9

what function has mg2+ ions

Answer 9

helps interactions between primers and phosphate groups of incoming nucleotides

Question 10

function of buffer

Answer 10

constant pH to stimulate taq polymerase activity

Question 11

function of PCR enhancers