Tuesday, March 31, 2009

Glass Knives

One of the best labs I ever took as an undergraduate was an advanced cytology lab where we learned to use the electron microscope.1 Part of the process was preparing thin sectioned material and that involved making our own glass knife that would cut very thin slices from wax-embedded tissue.

Here's a video from Leica showing how it's done today.2

I was reminded of this recently when I had occasion to refer to an electron micrograph taken by Harrison Latta. Latta invented the glass knife back in 1949. You can read about his discovery in this tribute to him on the University of California, Los Angeles, website.

This is one of those simple technological innovations that made a huge difference but would never have been recognized by the Nobel Prize committee.

1. Yes, they had electron microscopes back in those days!
2. You can also buy diamond knives but that's a lot less fun.


  1. Hi there,

    I've been following your blog for about 2 weeks now and it seems like a good time to pop out of lurkdom. Very interesting blog, I'm here to stay. I'm a chemist in the uk and when I was an undergraduate I had lectures only abut the EM. I'd love to have a go at one, thanks for the great vid showing one in use. I expect these days they are much more expensive and possibly smaller? Oh yeah I'm afraid I have a terrible terrible confession to make. Not only am I an atheist but I'm a Richard Dawkins fan as well.



  2. Nice video.

    A skilled knapper may produce a stone knife with an edge no thicker than one molecule from a core of obsidian.

    Of course, it may not work well for the lab, but ancient man was using glass knives well before Latta was even born.