Note: Any tips will go straight to our charity "TReND in Africa" (www.trendinafrica.org) which is dedicated to fostering university level science education on the African continent!
Simple framework to hold a histology sample above a Raspberry-Pi (RPi) camera fitted with an acrylic lens to generate a half-descent, low cost microscope. Shown in the images is a brain-slice from rat focussed on the hippocampus and a piece of 3D printing garbage. "Magnification", with a large screen as shown, is in the order of x100.
CHECK OUT OUR SCIENCE IN AFRICA NGO:
TReND in Africa gUG: http://trendinafrica.org/
A registered charity run by volunteer scientists on 4 continents
Help us design good, affordable lab equipment for African scientists!
Join us! Sponsor us! Spread the word. Thank you!
Also, check out our dedicated lab.equipment tinkering page: http://open-labware.net
The idea is pretty similar to my "phone-scope (http://www.thingiverse.com/thing:280004)" - but image quality is much better (as the RPi camera is great for macro) and here I have a proper focus drive as well as XY-table. A raspberry pi costs about 30$ and the camera another 10$ - so it's a quite cheap solution for a simple, yet half-descent microscope (e.g. for teaching).
Note: Acrylic lense does, like basically any plastic, filter UV. So in principle it should be possible to get fluorescent images out of this by using a strong UV-LED and hope for the best in terms of UV filtering with the lens. If this doesn't work ( I havent tried) try adding some cheap sunglasses, or indeed any odd bit of plastic under the sample for extra UV filtering.
For lenses, see the phone-scope (http://www.thingiverse.com/thing:280004).
For instructions how to fit continuous rotation servos if required (like this one could turn this into a fouuly automatic 3 axis control system) see my manipulator (http://www.thingiverse.com/thing:239105). Here you also find detailed instructions how to assemble the manipulator part.
The LED shown can be driven by the GPIO ports of the RPi if required - it's quite simple to do if you know some basic python or have used an Arduino before - it's very similar. I have a silly little python script that controls both the RPi camera and an LED - msg me if interested (but you are probably better off writing your own if you know what you are doing, mine really is very silly indeed)