Yesterday I made the rather grandiose claim that electron microscopes couldn’t be used to observe living tissue or organisms, since samples had to be sliced very thin for a TEM or dehydrated and coated in gold for an SEM. I’ve since learnt that there is something called an Environmental SEM, which allows the viewing of samples in liquid, under high pressure, and can be used for observing living organisms.
My questions: How common are ESEMs? Are they more or less expensive than traditional SEMs? Are most electron micrographs that you see taken with TEMs or traditional SEMs? Can you really use an ESEM to observe, say, a tadpole, and leave it completely unharmed?
Anything else you want to tell me about the production of electron micrographs and living tissue or organisms is gratefully welcomed.