I would like to do a quick freeze on pancreas from mice. I want to then make sections (30 µm thick). The idea is to preserve a fluorescent staining done in vivo.
I do not know if I should place my fresh tissue directly into liquid nitrogen, then embed the tissue in OCT, and then freeze everything in cold isopentane?
Or do I have to embed the fresh tissue in OCT first, prior to putting everything in nitrogen?
Or is there another protocol to do quick freezing in order to do sectioning?