If you want to examine the results of gel electrophoresis — and who doesn’t — you need a transilluminator. These devices can be quite pricey, though, so you might want to check out [Gabriel St-Pierre’s] plans to make an affordable blue-light version. You can see a video about the device below.

Using a UV filter, an Arduino Nano, an LED strip, 3D printing, and some mechanical items, it looks like this is a very easy project if you need such a device. There are a few miscellaneous parts like a hinge and some mirror material, but nothing looks too exotic.

If you need a refresher, electrophoresis uses an electric charge to separate material and shorter bits of material move faster, which means different clusters of molecules have similar lengths. The gel used is too fine to pass proteins, so they remain behind. A stain helps make things like DNA, RNA, and proteins visible but requires the right light wavelength. That’s the purpose of the device.

If you want to do the entire setup, you can find instructions to do the work with a handful of 9V batteries. We’ve covered a simple setup, too. If you prefer your DNA even more visible, we suggest this lamp.