Re: [DIYbio] Re: New

"I don't think [heatsinks] are useful for heat transfer through plastic vials. Oh well .."

That's an interesting comment. However could not the same be said for the liquid medium in which the vials are contained? How useful are plastic vials in this context, when you want to get things to temperature quickly in as few intermediate steps as possible? Why isn't glass used instead?

Also if this is the case I presume it is the volume of the liquid medium that is likely to have the greatest cooling and heating effect on the sample and that a large volume of liquid therefore would have the greatest effect in this heating and cooling process? Are rapid changes in temperature beneficial, or are more gradual changes preferable?

Also if getting to each temperature quickly and efficiently is the main goal, then presumably the purpose of a heatsink should be to have the capacity to cool the liquid medium as efficiently as possible? There are many ways this could be achieved, as those familiar with working with CPU cooling methodologies might be aware. (Like a water cooling via a radiator and a pump etc.)

Lastly in PCR (in my limited experience) I have tended to find that water is used as the main thermal medium. However I am aware that there are other potentially more efficient thermal mediums that can endure much more rapid heating and cooling cycles, should this be preferable?

On Monday, 2 June 2014 23:06:51 UTC+1, John Griessen wrote:

On 06/02/2014 04:38 PM, Jebus Jones wrote:
> But (as I recall) it was milling out that heatsink from a solid block of aluminium (or aluminum since you're American) that proved
> the stumbling block. I just don't have the equipment lying around to do this.

Heat flow can be equilibrated quickly bystirring vigorously. Big hunks of metal are not needed.
vigorous stirring of fluid, (which can be air), around your test vials is just as good
as fancy machined metal for transferring heat.  Controlling heat is easy for microcontrollers,
just throwing switches, (and needing only cascades of heavier and heavier switches to get up
to high powers of some heaters).