Dropped cells into liquid nitrogen tank - (Oct/11/2011 )
I made a big, very stupid mistake today in which an entire stick on which 6 cryovials of a rather expensive cell line ended up being dropped into the tank of liquid nitrogen. 5 of the 6 vials on the metal stick fell off upon collision with the bottom of the tank and now are residing somewhere down there at the bottom of the tank.
Any suggestions for ways in which I can retrieve these vials from the bottom of the tank of liquid nitrogen?
might sound crazy..but wait until the liquid nitrogen evaporates or if you have other dewar then remove the liquid nitrogen somewhere else in the mean time. Then if you can look at the vials, there is this fork looking metal stuff you can reach into the liquid nitrogen and take it out. Otherwise, vacate the rest of the cells in -80 for few minutes in a pre-frozen styrofoam container, empty the dewar and flip it upside down to get your vials and then put everything back in. If I can think of easier ways I'll write back.
This happens on a regular basis in our Institutes. You have to be extremely careful with LN2 as it is very cold (-196oC) and expands in air rapidly and can deplete oxygen levels very quickly. Follow these steps is you can:-
Take the dewar outside in the open air i.e. a deliveries yard for example
Use full face protection and long gloves.
Get a spare dewar, fill it with LN2 and place the columns from the original dewar in to that one.
Pour off VERY SLOWLY as much of the LN2 as you can from the dewar that has the cryovials at the bottom.
Once empty up-end the dewar and the vials will fall out.
Quickly reposition them into the columns/canes.
Refill with LN2
YOU MUST HAVE AN EMPTY SPARE DEWAR AND ALSO HAVE AN OUTSIDE SPACE.......WHICH IS NOT A BASEMENT AREA.
Hope this is useful.
Or why don't you try to refill the tank with LN2 more than the normal level this will make the vials go up and you could take them with metal claws. (I think is easyer, than take out all the vials from the tank just to save 5 vials) also remember that could be dangerous to your cells if start to thaw.
Hope this is useful for your problem