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    (Original post by Mrs Carrothead)
    I'm most surprised by the fact that there's an advertising slogan for DNA Polymerase....
    They're really branded - in fact, there may be a brand called HotStart...
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    (Original post by Athena)
    I'm sorry, but doesn't "Hot Start, Strong Finish" sound like a chat-up line, and not the advertising slogan for AmpliTaq Gold® DNA Polymerase? Scientists are all sniggering adolescents at heart.
    Have you seen the epMotion advert? Pipetting hasn't been the same since:
    http://uk.youtube.com/watch?v=J0s0Y3-BCaw
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    I know nothing of science, but with the -ase on the end I presume it's an enzyme? Does it break up DNA? And if so, how many people in the world are actually USING this stuff?!:confused:
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    (Original post by cpchem)
    Have you seen the epMotion advert? Pipetting hasn't been the same since:
    http://uk.youtube.com/watch?v=J0s0Y3-BCaw
    Because scientists are just that cool :cool: And very true, I was a happy bunny the day the lab head let me play with the automated pipette!

    (Original post by Mrs Carrothead)
    I know nothing of science, but with the -ase on the end I presume it's an enzyme? Does it break up DNA? And if so, how many people in the world are actually USING this stuff?!:confused:

    It is indeed an enzyme, from a microorganism that can survive in hot springs, and therefore has a polymerase (an enzyme that make DNA replicate exponentially) that can withstand very hot temperatures (close to boiling). Every lab in the world doing anything involving DNA (which is a LOT of labs) will have some form of Taq polymerase. It made the polymerase chain reaction possible. The joys of PCR: http://uk.youtube.com/watch?v=x5yPkx...eature=related
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    "PCR... when you need to find out who the daddy is... PCR... when you need to solve the crime!"
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    (Original post by Athena)
    "PCR... when you need to find out who the daddy is... PCR... when you need to solve the crime!"
    Oh dear, I'm sensing the kind of mental break that can only come from working on the same thing for more years than sane people can stand :sigh: .

    I'm watching United States of Tara whilst reading about 'the Congo'. Firstly, I don't know whether it's any good; it's still loading, but who knows, it's on Showtime :cool: . Secondly, wouldn't it be great if when people are talking like they know SOMETHING about the world, they'd use actual countries. For instance I'm just guessing this guy's talking about the Democratic Republic and not the Republic, but who knows?! That's half the fun! :sigh:
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    (Original post by Athena)
    Because scientists are just that cool :cool: And very true, I was a happy bunny the day the lab head let me play with the automated pipette!



    It is indeed an enzyme, from a microorganism that can survive in hot springs, and therefore has a polymerase (an enzyme that make DNA replicate exponentially) that can withstand very hot temperatures (close to boiling). Every lab in the world doing anything involving DNA (which is a LOT of labs) will have some form of Taq polymerase. It made the polymerase chain reaction possible. The joys of PCR: http://uk.youtube.com/watch?v=x5yPkx...eature=related
    Out of (bizarre) interest, what use is the high-temperature stability, in a lab setting?
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    (Original post by cpchem)
    Out of (bizarre) interest, what use is the high-temperature stability, in a lab setting?
    Heat cycles - you need to melt the DNA double strands apart so that you can use them as templates for copying more DNA (which the DNA polymerase does), and if you don't have an enzyme that can withstand the heat then you have to keep readding new stuff, which is expensive and not exactly feasible.
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    (Original post by ixivxivi)
    Heat cycles - you need to melt the DNA double strands apart so that you can use them as templates for copying more DNA (which the DNA polymerase does), and if you don't have an enzyme that can withstand the heat then you have to keep readding new stuff, which is expensive and not exactly feasible.
    I'd have thought you'd use helicase for that - surely that would allow gentler conditions than heating?
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    (Original post by cpchem)
    I'd have thought you'd use helicase for that - surely that would allow gentler conditions than heating?
    I always wondered why we don't use helicase, but I think there must be some advantages to PCR and Taq, like being able to readily stop and start the reaction (which, if the enzyme liked more ambient temps, would be more of a fiddle). Or else, the technology for denaturing and annealing DNA developed before they could mass produce helicase.
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    (Original post by Athena)
    I always wondered why we don't use helicase, but I think there must be some advantages to PCR and Taq, like being able to readily stop and start the reaction (which, if the enzyme liked more ambient temps, would be more of a fiddle). Or else, the technology for denaturing and annealing DNA developed before they could mass produce helicase.
    That makes sense... I suppose if helicase could be inhibited by something simple, that could work - but I'd imagine it's not that easy.

    Meh... I'm a chemist... albeit one taking the evil biological, genetic, protein-y option...
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    (Original post by cpchem)
    I'd have thought you'd use helicase for that - surely that would allow gentler conditions than heating?
    I have vague notions that helicase is relatively slow... mmm, googles
    Oh well, here you go: Helicase-dependent amplification.

    I'd guess, along with the lower sensitivity mentioned in the wiki (which is the one of the big things about pcr), using more enzymes might work out to be more expensive than the heating process? I'd never really thought about it (bad oxford student). Apparently helicase normally can only separate short-ish lengths of DNA before it falls off (which I guess applies to its in vivo function of opening bubbles of DNA single strands to copy mRNA/new copies of the DNA from), but apparently if you fuse it with a DNA pol it sticks around for longer. Apparently it's cheaper and quicker as well, which messes with my prev ideas.

    I guess the short splitting span of helicase would be the reason it didn't get used originally/that they just didn't think of it - it took people relatively long and the gain of the nobel prize to think up the simple-now-we-know-it concept of pcr...
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    Stupid question I know, but why is it that you can't just use RNA? Have we not yet worked out how to replicate DNA the same way the body does?

    Actually, probably just ignore that question. It's the wine talking.
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    god I leave for an hour and we're back to science chat.

    Athena, can you bring my leotard tomorrow night, I'll bring my cheque book to pay whats his face.
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    (Original post by ixivxivi)
    I have vague notions that helicase is relatively slow... mmm, googles
    Oh well, here you go: Helicase-dependent amplification.

    I'd guess, along with the lower sensitivity mentioned in the wiki (which is the one of the big things about pcr), using more enzymes might work out to be more expensive than the heating process? I'd never really thought about it (bad oxford student). Apparently helicase normally can only separate short-ish lengths of DNA before it falls off (which I guess applies to its in vivo function of opening bubbles of DNA single strands to copy mRNA/new copies of the DNA from), but apparently if you fuse it with a DNA pol it sticks around for longer. Apparently it's cheaper and quicker as well, which messes with my prev ideas.

    I guess the short splitting span of helicase would be the reason it didn't get used originally/that they just didn't think of it - it took people relatively long and the gain of the nobel prize to think up the simple-now-we-know-it concept of pcr...

    I'd imagine the problem is that PCR does work pretty well, everyone uses it, it's well understood, and there's a lot of research been done into the technology for it. Which might weaken the desire of scientists to switch, and of companies to develop an alternative. And I wonder if helicase amplification requires a lot of other extra enzymes that you don't need for PCR?
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    (Original post by Mrs Carrothead)
    Stupid question I know, but why is it that you can't just use RNA? Have we not yet worked out how to replicate DNA the same way the body does?

    Actually, probably just ignore that question. It's the wine talking.
    I've often thought this, and I don't really understand the way the body replicates DNA well enough to imagine a way of doing it effectively in a test tube. It's not a silly question

    (Original post by vapid slut magician)
    god I leave for an hour and we're back to science chat.

    Athena, can you bring my leotard tomorrow night, I'll bring my cheque book to pay whats his face.

    The science chat makes me feel less bad about being on TSR when I should be doing interview prep :p: And yes, I will certainly bring your leotard.

    Urgh, college politics have reared their ugly head again. Can't decide whether to dig my heels in and put time and effort into making sure I'm not blamed for something that isn't my fault, or else just say **** it, does it matter when I've got nothing to do with the SU any more and they're totally powerless?
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    You could always punish college by getting arrested in an embarrassing situation and drag their name through the press. It's proven to work.
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    I drank the bottle. It was a horrible mistake, I know it was, and now I've got two more books to read and I really really can't be arsed. And I'm also disturbed by how little the wine affects me. As they say, enjoy it while you're a student, because in later life it's called alcoholism .
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    (Original post by Athena)
    I've often thought this, and I don't really understand the way the body replicates DNA well enough to imagine a way of doing it effectively in a test tube. It's not a silly question



    The science chat makes me feel less bad about being on TSR when I should be doing interview prep :p: And yes, I will certainly bring your leotard.

    Urgh, college politics have reared their ugly head again. Can't decide whether to dig my heels in and put time and effort into making sure I'm not blamed for something that isn't my fault, or else just say **** it, does it matter when I've got nothing to do with the SU any more and they're totally powerless?
    Is this the election-y stuff I saw in the Cherwell? What exactly was the issue?
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    (Original post by Athena)

    I'd imagine the problem is that PCR does work pretty well, everyone uses it, it's well understood, and there's a lot of research been done into the technology for it. Which might weaken the desire of scientists to switch, and of companies to develop an alternative. And I wonder if helicase amplification requires a lot of other extra enzymes that you don't need for PCR?
    I know, I was going to say that even if it does manage to be refined properly, then you might get problems with scientists being conservative & wanting to stick with the methods they know work/ get use out of their expensive PCR machines.

    There's a paper from 04 (there's quite poss more recent ones, but I can't be arsed searching) here which seems to say that it might be useful in field situations etc where you don't have access to the machinery. I guess the expenses argument could be pretty big though - the whole humungous cost of sequencing big lots of DNA/all the potential advantages of just being able to sequence a whole genome quickly & easily to find mutations, instead of long-term searching with slow slow narrowing down to certain regions. I know one scientist who seemed really keen on the idea of sending huge swathes of DNA off (on a plane, to america :confused: ) to be sequenced and was into the idea of that (except I'm not sure how aware he was of helicase CR). hmm.
 
 
 
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