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CPU's Heat Output to Amplify DNA Could Make Drastically Cheaper Tests
MTorrice (2611475) writes "Researchers have harnessed that heat from a computer CPU to run the polymerase chain reaction (PCR) to amplify DNA in a blood sample. The team developed software that cycles the temperature of the CPU to drive PCR's three distinct steps.The method allowed them to detect miniscule amounts of DNA from a pathogenic parasite that causes Chagas disease. They hope their technique will lead to low-cost diagnostic tests in developing countries." (Always good to put waste heat to a practical purpose.)
The big deal is they could do this with the existing machine, and they didn't need to make modifications.
Waste heat has nothing to do with it.
Has this summary been round-tripped through Google translate, or is it just a jumble of random words?
$ctrPCR = 3;
do {
print "Cooking...Iterations left: " . $count ";
$count--;
} until ($ctrPCR == 0);
print "DING...Please wait 1 minute as product will be hot to the touch.\n";
If you don't want to be redirected, go here: http://cen.acs.org/articles/92/web/2014/09/Computers-Heat-Sink-Used-Slash.html Shortened URLs should be banned on Slashdot. Who types in URLs from a website? Just click it or copy+paste.
In addition to the computer and cell phone, the equipment and reagent costs for this new method are $41.50, far less than standard PCR equipment that costs about $19,000. The team hopes their low-cost method will allow diseases such as Chagas to be better monitored and treated in the field.
The takeaway is that PCR equipment sounds far more expensive than it needs to be. Not being a medical professional, I really hope they are more than just adjustable heaters. These guys are putting tiny test tupes into the fins of a CPU heatsink and giving it busy work to change the temperature. A cell phone app is used as the controller.
Clickable version of the link
They should have been using a standard heater, using the CPU's chip seems like a kludge.
It might work, but it seems unlikely to be the better than a purpose built device. At most it saves a bit of cash and energy, at the expense of accuracy and complex programming.
excitingthingstodo.blogspot.com
This reminds me of a CPU fan that is powered by the heat using a tiny Sterling Engine. Maybe not the kind of "practical use" of the waste heat the editor had in mind, but still an interesting idea.
Don't try to out wierd me, three-eyes. I get stranger things than you, free with my breakfast cereal. --Zaphod Beeblebr
The process they invented requires a heat cycling of the materials to work and knowing that computers are readily found almost everywhere, they wrote a small app which causes a computer CPU to generate heat cycles as needed. So it's really not waste heat since the purpose of the application is to generate this heat.
Do you really want to stick a whole PC in a lab, expose it to chemicals, and put its CPU through repeated heat/cool cycles just to save on a thermocycler?
They mention costs like $19k to obtain one otherwise. I'm sure they sell for that much just as I'm sure you can go spend $2000 on a linux license, but all a thermocycler needs to do is heat samples and cool them. Clearly the CPU isn't going to be a high-performance cycler - you could probably build a little cycler that just uses radiative cooling and some resistive heating for $50. I see peltier heat sinks selling for $40 these days, so I'm sure for $100 you could build a thermocycler on the cheap.
An ideal thermocycler just needs to heat samples to about 95C for a few seconds, cool them down to about room temperature for a few seconds, and then hold them at something around body temperature for a minute or two, The time spent ramping temperature up/down is basically dead time, and you have to repeat this 20-30 times, so if your cycler can change temperature in seconds instead of minutes you can save a LOT of time per test. Peltier effect tends to be the way things are done, or at least it was back when I was using these in the labs.
It looks like openpcr.org has a unit for $600. I'm sure it could be improved on, but I imagine that as you get cheaper, you lose precision, and that does matter. I can't imagine that a CPU can maintain a temperature +/- 0.5C without quite a bit of effort.
A PCR reaction needs 3 temperatures - a denaturing temp (usually 95C), an annealing temp (usually around 55C), and an elongation temp (usually around 75). The reaction is cycled between the temperatures to cause a 2^n increase in copy number in the reaction where n is one cycle through the temperatures.
A low-tech heating solution could be obtained for less than $50, would not require any special modifications of reaction conditions (the article states that they used DMSO to lower the denaturing temperature), and would not require you to open up a computer case in a low-tech environment.
Useless publicity stunt.
Obviously they use the spacebar to toggle the heat on and off. https://xkcd.com/1172/
PCR Thermal cyclers, especially ones without fancy accessories, are very cheap.