My dad has described the process for cutting sections to be viewed under microscopes, including electron microscopes. Sharpening the special blade prior to this was routine and he offered to give the sharpening rig, which I declined, as I can achive any practical edge by hand, for a wide variety of uses, and generaly have to be carefull with any blade that I fuss with at all, there's sharp, and theres dont fuck up with this. So I always wonder at peoples drive to get things sharp, frozen sections have an absolute need for a very very clean cut, but nothing else I know needs that.