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Eppendorf popup toaster

Nichey
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This is a very niche product, so feel free to move along.

The average molecular biologist spends 7.3 minutes per day defrosting frozen solutions. Typically, these are in standard 1.5ml microfuge tubes (Eppendorfs to you and I, if you are also a molecular biologist). Most biological reagents are stored at -20°C.

The standard method of defrosting Eppendorfs is to hold them in the fist whilst being impatient. Occasional shaking, to and fro, slightly accelerates the defrostage, but does not look good.

Yes, you can use a dri-block or pop your tubes in a handy incubator or waterbath, but this is a pain.

What is needed, therefore, is a simple pop-up Eppendorf defroster. Powered by a USB connector for simplicity, it is rather like the bastard child of a vehicular cigarette lighter and a pop-up toaster. Simply pop the Eppendorf in, press it down, and it will be gently but speedily warmed until it reaches room temperature. Thereupon, it will pop up, ready to use.

MaxwellBuchanan, Sep 28 2017

bs0-brand productivity-enhancing buffer http://www.nature.c...d_name=subjects_dna
[bs0u0155, Sep 28 2017]

Tiny Peltiers http://www.customth...0-08RA_spec_sht.pdf
[bs0u0155, Sep 29 2017]

Call that tiny? http://www.heat-man...en/1stagemiscro01_k
[MaxwellBuchanan, Sep 29 2017]

[link]






       When the weather gets hot I ride the Moto Guzzi to and fro with artificial ice cold packs in my shirt pockets.   

       Perhaps you could hire a motorcyclist to ride around for you. No, strike that.   

       Buy a motorcycle.
normzone, Sep 28 2017
  

       Why not just take you -20C tube and shove it up your ...   

       Ummm, maybe not.   

       But it would defrost quite quickly ...
8th of 7, Sep 28 2017
  

       Would it be a fair assumption that molecular biologists run on the occasional cup of tea or coffee?
Ian Tindale, Sep 28 2017
  

       It would. However, the Health and Safety czars perpetually try to dissuade scientists from having hot (or even cold) drinks in the lab.
MaxwellBuchanan, Sep 28 2017
  

       Is a czar roughly equal to a dean?
Ian Tindale, Sep 28 2017
  

       //The average molecular biologist spends 7.3 minutes per day defrosting frozen solutions.//   

       The average cell biologist spends 73 minutes per day defrosting frozen solutions... One tactic is to take the two 50ml frozen falcon tubes and put one each in the trouser pockets. It still takes a few minutes, so why not get a little sun and a coffee? The growing damp patches caused by the 80% humidity condensing on the front of your jeans acts as a wonderful charity-mugger deterrent.   

       Anyhow. Just swap out your solvent, even fussy old DNA is happy in antifreeze <link>   

       //It would. However, the Health and Safety czars perpetually try to dissuade scientists from having hot (or even cold) drinks in the lab.//   

       This sentence could end 10 words earlier.
bs0u0155, Sep 28 2017
  

       No. A dean - in places that have one - is typically an elderly person with considerable experience but no actualy power. A czar, in the present context, is someone who is typically young and with no understanding of anything, yet who paradoxically has immense power over everyone else.
MaxwellBuchanan, Sep 28 2017
  

       " One tactic is to take the two 50ml frozen falcon tubes and put one each in the trouser pockets. It still takes a few minutes, so why not get a little sun and a coffee? The growing damp patches caused by the 80% humidity condensing on the front of your jeans acts as a wonderful charity-mugger deterrent. "   

       The average home brewer spends an indeterminate amount of time bringing vials of yeast from refrigerator to room temperature in the same manner. Time estimates are uncertain at best, as usually by that time in the process much ale from the previous batch has been consumed.   

       My safety czar has authorized me to cover the kitchen in fire extinguisher product anytime I choose. She says she'd rather clean all that up than talk to the fire department.
normzone, Sep 28 2017
  

       Wait... what you're describing is an electrical device for rapidly changing the temperatures within Eppendorf tubes in a controlled manner. If only there were one already in the lab? We used to have one, I think it became a "shared resource" and as such all PCR now involves a trip to Cleveland.   

       Actually, a USB-thermal cycler is easily doable. You could do say, 1 tube with standard usb which are all about an amp nowadays, or use 2 ports. Certainly these Peltier elements <link><link> flow about a Watt, which for a 50ul PCR reaction gets you 5C/second if you ignore the tube etc, so say 3C/second? Are there problems associated with the rate of change?   

       Anyhow, you need a little Peltier attached to the bottom of a little aluminium tube holder, wrap in insulation, place inside much larger casing which doubles as a heatsink, maybe a relay. You can probably get away without a temp sensor if you know enough about the Peltier. The microcontroller, screen, transformer, casing all unnecessary, control software trivial, it's already USB.   

       For a bit more oompf, a slightly more robust Peltier and a chunky capacitor would solve the transient high power demands.   

       With USB-C the power problem goes away and a full-spec version is easy. Perhaps a little more messing with the complex interface.
bs0u0155, Sep 28 2017
  

       Thermocyclers generally take 0.2ml tubes, which defrost in a moment in your hand anyway. Plus they're bulky and not particularly cheap. I'm thinking of something cheap-n-cheerful for 1.5ml tubes, that everyone can have on their bench.   

       And yes, a USB thermocycler is doable, though it would be small and probably only take a few tubes. A reasonably fast 96-well cycler takes about 10A at 12V.
MaxwellBuchanan, Sep 28 2017
  

       What's needed obviously is a combination of dean and czar. A czar/dean.
Ian Tindale, Sep 29 2017
  

       It sounds like you need a lump of plutonium with holes drilled in it to accept the Eppendorf tubes. Have this in a handy place on your lab-bench. Then just drop the tubes in it for a few seconds and the heat generated by the radioactive decay in the plutonium will be enough to defrost the solution.
hippo, Sep 29 2017
  

       //What's needed obviously is a combination of dean and czar// - clearly, a combination of a DEan and a czAR is a 'Dear'...
hippo, Sep 29 2017
  

       Is a scientifically standardized defrost method needed?
wjt, Sep 29 2017
  

       That's an interesting question.   

       Some things are sensitive to the rate of freezing. For instance, if you're freezing live cells, the rate of cooling matters a lot. And for non-living solutions, the rate of freezing can affect how the solute partitions (slower freezing tends to concentrate the solute in the last-frozen part).   

       For defrosting, I'm not sure. In most cases it won't matter, but there are exceptions. For instance, if you're defrosting frozen bacteria, it's necessary (in some situations) to do so slowly, so that no part of the liquid gets much above zero degrees. The same is true for some temperature-sensitive compounds.   

       But, 99 times out of 100, you just want to defrost the solution quickly but gently.
MaxwellBuchanan, Sep 29 2017
  

       Thermite.
8th of 7, Sep 29 2017
  

       Set up a lab-adjacent bakery and lab mice production facility. Bakery bakes bread, mice chew eppendorf tube sized holes in bread, bread is placed into glovebox, eppendorf tubes are placed in fingers of glovebox and fingers are inserted into eppendorf sized holes in bread. Following removal of warmed tubes / gloved, hollows in bread are filled with garlic butter and passed to me, for recycling.
calum, Sep 29 2017
  

       //But, 99 times out of 100, you just want to defrost the solution quickly but gently.//   

       I think a big part of the problem is the success of the Eppendorf tube. For those not in the know, it's a little flip-top 1.5ml polypropylene container with a conical bottom. They're cheap, everywhere and so are used for everything. They were not designed for storage, or melting/freezing, they were made so tough and relatively thick because they needed to stand up to high G centrifugation. There's probably a few things to be done that could improve them, for one, I'd like to see harsh but punitive tax imposed on companies that continue to make such tubes in EXACTLY THE SAME COLOUR AS ICE. I suspect millions a year are wasted because of invisible tubes. You could also play with the properties of the plastic to increase thermal conductivity, I know PTFE with glass microparticles has been used to increase heat transfer by 50% or so.
bs0u0155, Sep 29 2017
  

       //EXACTLY THE SAME COLOUR AS ICE// The answer, therefore, is to make the ice a different colour. The pigments in some coloured Eppendorfs can, and do, leach into solutions. We (and by that I mean me and some other people) spent a week trying to find out why our 4-colour supersensitive fluorescence assay was giving a huge signal in one channel. It was pigment leaching from the polypropylene.
MaxwellBuchanan, Sep 29 2017
  

       bilayer plastic, color on outside
beanangel, Sep 29 2017
  

       Eppendorf tubes are produced and used by the gazillion, and presumably are made by injection moulding. Cheap and simple is good.
MaxwellBuchanan, Sep 29 2017
  

       //EXACTLY THE SAME COLOUR AS ICE//   

       <pedantry>   

       Pure ice doesn't have a colour - it's transparent,   

       </pedantry>
8th of 7, Sep 29 2017
  

       sp "blue".
FlyingToaster, Sep 29 2017
  

       <balancing hands> meaning ... pedantry , pedantry...meaning </balancing hands>   

       PS technical out.
wjt, Sep 30 2017
  

       It occurs to me that the inductive effect of wrapping an ordinary mains cable (for example, a standard IEC connection cable) in a very tight set of many turns would give enough of an inductive load to get desirably warm. Of course, too tight and it'll be undesirably warm.
Ian Tindale, Oct 11 2017
  
      
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