Biology Forum Molecular Biology PCR question

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    • #10645
      thewax
      Participant

      Why is there a need for PCR when there is helicase-dependent amplification??????
      In http://en.wikipedia.org/wiki/Helicase-d … lification, wikipedia states that HDA takes longer than PCR. My question is [i]WHY[/i]?????? [Even though the helicase might unwound it slowly (as evident in DNA replication) it’s not as if the DNA polymerase can elongate the growing DNA strand any faster (again refer to DNA replication), right?????]

    • #88052
      thewax
      Participant

      Can anyone help with this question????????

    • #88066
      blcr11
      Participant

      That wiki article was probably posted by someone from the kit manufacturer. You probably should consider it a bit of advertising. I don’t know anyone using this alternative to pcr. The only "advantage" I can see is the ability to run everything at one temperature, and I don’t see that as a great plus. If the method was obviously superior to pcr it would be widely used already. I suspect it does not work as well as advertised.

    • #88082
      thewax
      Participant

      Thanks!!!!!! 🙂

      But why wouldn’t it????
      I mean, compare the helicase and DNA polymerase to those used in DNA replication (they are the same, and in DNA replication, they move really fast), right?????????

    • #88092
      mith
      Participant

      http://www.nature.com/embor/journal/v5/ … 00200.html

      lacks refinement, doesn’t work on long seqs, but it’s interesting enough to be in nature

    • #88108
      thewax
      Participant

      hmm… so HDA is pretty efficient….., right?????

    • #88349
      Sepals
      Participant

      The article lies. PCR does denature DNA, at around 95C. So therefore it must become unwound for the two strands to separate. Never use wikipedia as an academic resource, it’s too untrustworthy and contrary to what some people say, it is not fully protected. I know from experience, it can be very hard to keep correct info on a page and permanently rid it of nonsense, as someone can easily vandalise it again.

    • #88350
      Sepals
      Participant
      quote thewax:

      Thanks!!!!!! 🙂

      But why wouldn’t it????
      I mean, compare the helicase and DNA polymerase to those used in DNA replication (they are the same, and in DNA replication, they move really fast), right?????????

      PCR is around 4 hours max if you use the maximum number of cycles (40) and normally 3 hours long. Surely 3 – 4 hours isn’t too long to wait. Inbetween you can get on with other lab work.

    • #88385
      thewax
      Participant

      cool!

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