Cryopreservation: Cells for the long-haul
When I was a kid, I saw a movie about a caveman that met his end by being unceremoniously frozen, found by an anthropologist some 11000 years later, and thawed in a lab. Naturally, he came back to life and lived in some sort of biosphere. True story (my recollection of the movie, not the reanimated Cro-Magnon). The premise was that you can freeze a body, which is apparently little more than a collection of cells, thaw it, and have the cells survive, and teach said bucket of cells Neil Young tunes (I’m serious. I saw this movie on HBO in the eighties). Now, with my fancy knowledge, I can safely call Bull**** on this movie based on one observation: The caveman wasn’t frozen with DMSO.
Dimethylsulfoxide, or DMSO, is a key ingredient in freezing medium along with a base such as DMEM and serum, whether it’s made in your lab, or bought from the good folks at Gemini. The DMSO is a permeabilizing agent that plays a few roles: It lowers the freezing point of the medium, and prevents crystallization of water (think tiny daggers piercing the cell walls, spilling cellular guts into the medium). Which is why, dear reader, I don’t buy the whole “Freeze a caveman now, and thaw later” bit that HBO movie tried to get me to believe as an impressionable youth. That guy’s cells must’ve been jell-o after he thawed, just a bucket of cytoplasm and a furry loin cloth. Anyway, I digress…
There’s also serum in your freezing medium such as FBS, horse serum, human serum. Some folks say “It’s so the cells don’t starve when you thaw them” while others say “it acts like a cushion for the cells.” I say “Yeah, sure. They both sound like plausible arguments.” Either way, serum seems to be a very important ingredient in freezing medium.
I used to make my own freezing medium. It was easy enough, with just a few ingredients. After all, what was one more medium on top of the half dozen or so I was making weekly anyway? Well, it turns out DMSO can go through latex and you can actually taste it when it gets on your skin. It’s like a magic bullet that hits your hand and exits your mouth. It’s kinda awful. I don’t recommend it. Moreover, I found out when I was running a lab for a pharmaceutical company, that DMSO changes its chemical properties over time, a possible red flag for people looking to use that dusty bottle of DMSO for their freezing medium. Then I found Gemini’s Vivify cryopreservation medium. I used it, and I liked it. Once in a while I visit my old lab. My stem cells are still around and they still seem to make all the cell types I used to make, so there’s some credibility for ya.
So, whether you make your own or buy it pre-fab, Gemini has quality stuff for your freezing needs. Give them a ring and see if you can score yourself a free sample.