Can you help me with an ongoing discussion:
Do you use Mr. Frosty at room temperature or pre-cool it to 4º when preparing chilled samples before putting it into the freezer? Either way, why is that your preference?
I actually keep my Mr Frosty at -20 so that the cells freeze very rapidly and are less susceptible to DMSO cytotoxicity. The cells then go straight into the -80 overnight then into liquid nitrogen or -150 the next day.
I guess it's personal preference.
I usually precool it to ~4dC, also add freezing medium at 4dC to minimize protease action. Following that, it goes to -80dC o/n (where the device supposedly works at the 'optimum' rate of 1dC/min temp reduction), before removal from Mr Frosty and transfer to lN2.
Hi I keep Mr Frosty at -20 for a day before using for cryopreservation purpose.
We just started trying this new product:
Claims to require no pre-cooling, and requires no isopropanol.
You are talking about CoolCell, a new cell freezing container, that does require no alcohol, no maintenance and no pre-cooling. Check it out at http://tinyurl.com/yh8b69k
I always precooled my Misters Frosty (the plural) to 4C and added 0C freezing medium to the cells. Cells often sat on ice for a bit if I had a lot of tubes at the same time.
I've been following a number of these Mr. Frosty versus Isopropanol-free systems threads and the one disadvantage I can see with the latter is that they only have enough space for 12 cryovials. The Isopropanol containing Mr. Frosty products that I use have space for 18 but this is also not really enough.
So to any product developers out there - design a foam based cooler that hold 30 vials and costs under $90. We'd probably buy 10 immediately! Also, for ease of storage in -80 freezers, they would work better if they were square and not round as this wastes precious space.
I totally second that - and if they happen to fit in the width of a standard freezer rack/box so that they can be neatly sloted between racks.... freezer bliss ;)
i drive a hummer myself - space trumps environment - more hazard but more space - if they could just make one that is bigger and needs no gas and fits into my garage that stores a lot of things i havent used in 50 years