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    I know that a primer is a short complementary piece of DNA
    But why is it used???
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    (Original post by Dan_Crew)
    I know that a primer is a short complementary piece of DNA
    But why is it used???
    It is used in PCR and is complementary to the original DNA piece, basically it binds to a certain part of DNA and the replication starts from the base where the primer ends.

    if this helps, I was told when we used them that the polymerase enzyme can't just start from nothing - it has to have an established bit of dna (the primer) to "sit on" and then moves along from there

    rosie
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    It simply indicates the part of the DNA to be copied

    (Original post by Roth)
    It simply indicates the part of the DNA to be copied
    but how?
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    (Original post by crana)
    but how?
    Primers have specific sequences of ~6 bases long. Logically, the complementary sequence to these will occur every 4096 (4^6) bases, and if scientists know the sequence of some DNA either side of the site they want to amplify, they manufacture primers specific to these sites, and as you say, they bind their complementary DNA, DNA Pol can bind and away goes the PCR!!!

    (NB, there are some more steps involved in localising the site, but it's mainly to do with complementarity of the primers.)

    (Original post by Helenia)
    Primers have specific sequences of ~6 bases long. Logically, the complementary sequence to these will occur every 4096 (4^6) bases, and if scientists know the sequence of some DNA either side of the site they want to amplify, they manufacture primers specific to these sites, and as you say, they bind their complementary DNA, DNA Pol can bind and away goes the PCR!!!

    (NB, there are some more steps involved in localising the site, but it's mainly to do with complementarity of the primers.)
    what i thought then
    ta
 
 
 
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