You can make your own USB microscope using an old webcam and a cheap toy microscope. All it takes is a soldering iron, some hot glue, and an hour of your time. Instructables user moris_zen has the details, which basically involves a little focusing trial and error before gluing things together:

While you view the image via the SW used for the webcam – position it so you get a clear image. You may need to play with it for a while. After you find the exact location use a hot glue gun to fix it to that position. Then tape the wires tidily to the microscope and start taking pictures…

I imagine you’d get even more interesting results substituting the old 320×240 web cam for an old 2 megapixel digital camera.

Also worth checking out would be to skip the optics entirely, positioning the CCD right up against the sample with a proper light source. I believe this is the technique being used in the UCLA cellphone microscope. The output is supposedly low-res and blurry, but it’s decent enough to capture the shadows of individual cells, making cellcount-based diagnoses possible.

Build a USB Digital Microscope
Aydogan Ozcan, UCLA Lensless Imaging System

  • Christian Berger

    Uhm, isn’t it a serious degradiation when you turn a normal microscope into an USB one? I mean those microscopes aren’t buildt for photography. The place where the image is sharp is not a plane, so you can either focus on the borders or the middle. This is no problem if you watch it with your eyes, but it is if you use a camera.

  • Tin Kan3

    It does specify “toy” microscope.

    I use a couple of different compact Canon 5 M-pixel cameras on my daughters microscope, with just a short length of poly-pipe and three nylon screws. It’s a university quality/standard machine, and I achieve quite good images, and video (should I need it), of up to 1000x.

    Of course having bit of ‘depth-of-field’ control helps a lot. I’m looking forward to when I upgrade my SLR gear to digital, and hooking that in…

    I guess the point is, you get what you’re prepared to pay for.

    I feel Jason’s put together an excellent entry level construct, ideal for stirring the interest of prospective Microscopers (a new word?).