Alternatives to ice when working with samples. - (Jul/14/2015 )
When working with samples, it is often required to keep these on ice at all times - even when working on them.
I wonder though... If I instead of using a ice-bucket with actual ice in it - instead substituted the ice with lots and lots of small stainless steel ball bearings cooled down to -20 to -22 degrees C - would they be able to keep cold for long enough in comparison with the real ice?
That would probably work, I would probably use them in conjunction with something like ice packs to do this if you want something re-usable. This would allow you to keep the bearings cold for longer, as the biggest problem would be conductance - steel conducts heat well, but ice doesn't so ice would keep colder for longer.
Note that in many instances you just want to keep the substance cold, not freeze it, which would be the risk you run when using frozen bearings.
Do you use a styrofoam box or ice-box? The insulation of the container is very important to keep the ice as ice for long.
Also, the thermal capacity of metals is low, so although the metal will cool faster, they will also reach room temp faster.
As said by bob1, you will probably freeze your samples.
As additional note, if you need to cool something fast, an easy and common method is using a slushy, mix ice and water until having some sort of watery ice, it has a higher cooling capacity.
Water-ice slush also has the virtue of near constant temperature -- definitely not the case with metal shot.
then again, lab armor has a bead based "ice" bucket. you can use them for heating as well as cooling.
or you could get something like this. it can be used to cool a block or the lab armor bead block.
In labtimes I read a tip to use cooled/frozen aquarium gravel (5-8 mm grain size) as substitute (just put the Styrofoam box with the gravels in a freezer to make it ready).
Reference: Anal. Biochem., 2015, 474, 38-39
mdfenko on Wed Jul 15 13:00:27 2015 said:
Did you check out the price-tag on those?
I think I will try out the aquarium gravel idea from hobglobin.
EDIT: Or maybe not... seems the gravel is simply.. rocks? might as well have gone with ball bearings I think.
I guess I will stick to actual ice instead. Although I was hoping for something reusable. :)
Oh, as for el Crazy's question: I havent bought a box yet, but I am looking at a styrofoam box made specifically for lab-work on e-bay.
what is holding me back is that the shipping cost is one third higher than the cost of the actual item. It just doesnt feel right. :(
but those boxes are super expensive new. I simply cannot grasp why they should be. Its styroforam... not platinum and gold...
Normally you reuse the styrofoam boxes from shipping enzymes or heat-sensitive products to the lab. I really never had to buy one.
I just searched for styrofoam boxes in both Norway as well as on E-bay. I had no idea it was going to be so difficult to get something as simple as a styrofoam box. haha! In Norway it is impossible to find anywhere...
On e-bay I find lots of them - that does not ship internationally.
I guess I'll buy some enzymes from Bio-Rad and hold on the ice in the meanwhile... haha! :D