I don't know, because I know nothing about PCR. But I'd guess that it has something to do with that line, "It's amazing what heating then cooling then heating again can do."
First up: I've worked in a lab doing PCR, and I'm in awe that people who don't know what it, is get anything out of that song.
PCR, polymerase chain reaction, is a process for rapidly producing large quantities of a piece of DNA of interest, also called "amplification". You know DNA is double-stranded, well, to copy it, you pull the two strands apart and each strand becomes a template for a matching new strand. That lets you create two double helices, which you can then pull apart and copy to make four, etc.
The easiest way to pull the two strands of DNA apart is to heat the DNA to 95C (just below boiling, I've never heard of PCR temperatures in F). The new strands are built by an enzyme called DNA polymerase. Unfortunately, most DNA polymerases are destroyed by 95C temperatures, so very early PCR involved heating the DNA to separate the strands, cooling enough to allow the DNA polymerase to not be destroyed when it was added, letting the DNA polymerase do its work, heating the DNA again, cooling and adding more DNA polymerase, etc. Tedious, time-consuming, and expensive in DNA polymerase.
Then some genius (Kay Mullis was given the Nobel prize for it, but there's some discussion in the community that the idea was already around) realised that specialised organisms that could survive in hot springs must have DNA polymerase that could survive high temperatures. So you would only need to add the DNA polymerase once at the beginning. Then you'd heat to 95C to separate the strands, and cool to about 72C (because this DNA polymerase can survive 95C but not actually do anything much up there, and is much happier doing its work at 72C), heat, cool, heat, cool, heat, cool, heat, cool - we did 30 cycles, but I've heard 45 cycles is quite common these days.
So a thermal cycler, also popularly known in labs as a "PCR machine" is basically capable of running a program of repeated heating and cooling, allowing the PCR reaction to happen in the test tubes or microtitre plates you put in the machine.
That's the simplified version, I'm happy to answer questions or describe stuff in more detail if you still care :-).
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I LOVED this song as a kid!!!
Date: 2008-01-17 12:09 am (UTC)OK, maybe it was "We Are The World" But, whatever, same thing...
BTW, I'm so proud of you that you fixed your washing machine!! :)
(no subject)
Date: 2008-01-17 01:12 am (UTC)(no subject)
Date: 2008-01-17 04:00 am (UTC)PCR and thermal cyclers.
Date: 2008-01-17 06:46 am (UTC)PCR, polymerase chain reaction, is a process for rapidly producing large quantities of a piece of DNA of interest, also called "amplification". You know DNA is double-stranded, well, to copy it, you pull the two strands apart and each strand becomes a template for a matching new strand. That lets you create two double helices, which you can then pull apart and copy to make four, etc.
The easiest way to pull the two strands of DNA apart is to heat the DNA to 95C (just below boiling, I've never heard of PCR temperatures in F). The new strands are built by an enzyme called DNA polymerase. Unfortunately, most DNA polymerases are destroyed by 95C temperatures, so very early PCR involved heating the DNA to separate the strands, cooling enough to allow the DNA polymerase to not be destroyed when it was added, letting the DNA polymerase do its work, heating the DNA again, cooling and adding more DNA polymerase, etc. Tedious, time-consuming, and expensive in DNA polymerase.
Then some genius (Kay Mullis was given the Nobel prize for it, but there's some discussion in the community that the idea was already around) realised that specialised organisms that could survive in hot springs must have DNA polymerase that could survive high temperatures. So you would only need to add the DNA polymerase once at the beginning. Then you'd heat to 95C to separate the strands, and cool to about 72C (because this DNA polymerase can survive 95C but not actually do anything much up there, and is much happier doing its work at 72C), heat, cool, heat, cool, heat, cool, heat, cool - we did 30 cycles, but I've heard 45 cycles is quite common these days.
So a thermal cycler, also popularly known in labs as a "PCR machine" is basically capable of running a program of repeated heating and cooling, allowing the PCR reaction to happen in the test tubes or microtitre plates you put in the machine.
That's the simplified version, I'm happy to answer questions or describe stuff in more detail if you still care :-).
(no subject)
Date: 2008-01-17 01:12 am (UTC)