MadSci Network: Neuroscience |
Hi Rachel,
I'm sorry that it has taken so long to address your question. Part of the delay has been due to none of us really being sure exactly what area of science your question belongs to. After several changes in category, it wound up in Neuroscience.
Carosafe is a product of the Caroline Biological Supply (CBS) company. It is a propylene-glycol based mixture that is used as a preservative for tissue specimens. As far as I can tell, it is usually used after the tissue has been fixed with formaldehyde (aka formalin) or sometimes alcohol, both to prevent tissue deterioration and the development of mold, and to reduce exposure to formaldehde.
The materials data saftey sheet (MSDS) (16k PDF) for Carosafe says that it is composed of Propylene Glycol, 2-amino-2-ethyl-1,3-propanediol, and Ethylene Glycol Phenyl Ether in addition to some residual formaldehyde from the fixation process. The MSDS also suggests that Carosafe is hazardous to the eyes, but of course this is in living organisms; the MSDS doesn't address the effects of Carosafe on fixed eyes.
That having been said, I called CBS, but I wasn't able to find out much in particular about the effect of Carosafe on lenses. So, I asked an entomologist friend of mine to take a look at some specimens. Here's what she had to say,
"I'm afraid I have no conclusive evidence on the effects of carosafe on eyeballs. I looked at some
pigeons, rats, smelly fish and salamanders pickled first in formalin and then in carosafe, which is
used mostly to make the formalin-soaked specimens safer for students to handle. So I also looked
at some fish in formalin, without carosafe, to see if there was any difference between those and
the carosafe treated ones. I couldn't see any difference.
"The eyes on the fish looked pretty normal, both with and without carosafe. Some eyes were a
little wrinkly, regardless carosafe or not. The pigeon and rat eyes, when I pulled back their eyelids,
were cloudy so you couldn't really see the pupil anymore, but I didn't have any non-carosafe
specimens to compare those to, so I don't know if that's the effect of carosafe or formalin or just
pickling in general."
Keep asking those questions!
Try the links in the MadSci Library for more information on Neuroscience.