You know how you sometimes pull something out of the freezer, like steak, and it's all freezer burned and looks really icky? Well, that's sort of what I've done to my fingers.
It was an accident, of course. I was at work and we had just received a shipment of embryos from a patient in Germany. Yes, people ship their embryos all over the world. I don't know what the situation is, so I don't know how the embryos ended up here. Anyway, when we got them we needed to unpack them, check all the paperwork and verify the vials with the paperwork, log them in to our system, and put them into cryostorage.
When we unpacked them, we saw that they were packed in a very unusual way. Firstly, there was supposed to be one straw of embryos, but we saw at least 6 vials and no straws. We freeze our embryos in vials, but many places freeze them in straws, which is just like it sounds - the embryos are in what looks like a four inch long tube a little smaller in diameter than a coffee stirrer straw. The embryos are inserted into the straws with liquid nutrient media, and then the ends of the straw are heat sealed to keep the embryos inside. Usually these straws are contained in a larger tube, which is snapped into a long metal holder (a cane) so they can be taken easily out of the shipping container. Secondly, upon searching around the shipper, we discovered that they had sent solution for thawing the embryos. This is really odd. Usually they just send a paper protocol for thawing and we make up the solutions if we don't have them already.
But we still couldn't find the straw of embryos. Forget the solutions, it's the embryos that are important. Between two of us, two forceps, and one flashlight, we finally located the straw of embryos. It was loose in the shipper, not protected by another tube and not attached onto anything. This is super scary, because the straw is very small and it could have been easily lost or overlooked.
When we had the straw, we now needed to get it into a tube, cap the tube, and then put the tube onto a cane. To make matters more difficult, we need to do all of this work with everything submerged in liquid nitrogen. Now, liquid nitrogen is cold. Remember those Timex commercials where they put a rose in liquid nitrogen, and once it was frozen they shattered it like glass? Well I'm here to tell you that liquid nitrogen will freeze damn near anything solid. And fast. But if that straw were to come out of the liquid nitrogen for more than a few seconds, the liquid inside the straw would thaw and so would the embryos. Not what we wanted to have happen.
With three of us working now with forceps and flashlight, and after dropping the straw once in the bottom of the liquid nitrogen bucket and having to find it and fish it out again, we had the straw safely inside a capped tube. Then we just had to get the tube on the cane. My boss and I put the tube on the cane, and she went to get a protective plastic sheath for the cane. I saw that the tube wasn't securely snapped into the cane, so I reached down with my bare fingers into the liquid nitrogen to snap it back on.
Now, liquid nitrogen is cold, but you can put your fingers in a for a second before it starts to hurt. Two seconds, tops. So I thought I'd just snap it back on and all would be well. However, once I touched the tube it fell off the cane. At this point, I'm committed and I have to put the tube back on the cane, securely this time. Which I do, but I can feel my fingers burning and I can hear them sizzle as they freeze. My boss sees this and says "Oh!". I pull my fingers out of the liquid nitrogen, and they are white.
Ack. This is not good. On a reflex I closed my hand into a fist and covered it with my other hand. My fingers felt numb and I was afraid to look at them again. My boss kept saying "Are you okay? Are your fingers frozen?" I said I was fine, and after a minute or so I opened my hand. Just the ends of my fingers were red, not frozen white, which was good. I had no feeling in them, but at least they didn't fall off or anything.
I really expected the tips to blister, but I got really very lucky and they did not. All I have on my middle finger is an angry red mark. All my fingers (except my pinkie and thumb) are really sore on the tips, so it makes doing my job, and typing, not very comfortable.
So, don't mess with liquid nitrogen, kids! You'll freeze your fingers off!
The Harmany Muzzle
3 days ago