Gel electrophoresis is a technique, used by microbiologist - biochemists - bio technologists, for the separation and analysis of various biochemical substances.
Here I've got a photograph of and gel electrophoresis unit from my college (Of course with permission of my teacher).
You can see the power supply wires (Black and Red) which gives electric current to the gel.
The gel can be seen in photo.
The separation of deoxyrebonucleic acid was going on while taking the picture (As per I know).
We can see two different bands of separated DNA in sky blue and nevy blue colours.
If you want notes on Gel electrophoresis or any technique related to microbiology please comment in any of my posts. I'll try to manage for you. Please dont forget to leave ur e-mail ID.