Polymerase Chain reaction Flashcards
what is pcr
it is a method of copying fragments of dna
why is it rapid
as the process is automated
in short terms what does the process require
the dna fragment to be copied, dna polymeras, primers , nucleotides, thermocycle
how is the dna strand seperated
placed in a thermocycles at 95 degrees causing the two strands to separate due to denaturation of the hydrogen bonds between the two strands
what else is included in the thermocycler
the primers and dna fragments and dna polymerase
how do we add the primers
the mixure is cooled to 55 causing the primers to anneal to the end of the dna fragment
why are the primers added to the end
provide the strating sequence for dna polymerase to begin copying dna as dna polymerase only attatch to nucleotides at the end of an existing chain
what else does primers do
prevent the two dna strands from simply rejoining
how do we synthesise dna
the temperature is increased to 72
why is it increased
this is the optimum temperature for dna polymerase to add complimentary nucleotides along each single strand of dna
what does this produce
two separate stands of the original strand of dna
what are the two advantage of invitro
extremely rapid and doesn’t require living organisms
how is it fast
it can produce billions of identical dna fragments
why may this also be a problem
it can also increase the amount of contamination as will copy contaminated dna so will result in a non functional gene
what else is a strength in terms of accessibility
it only requires a small amount of dna for replication
