Thank goodness for Learn.Genetics! It would be great to demonstrate gel electrophoresis for my students, but there are just so many variables that can go wrong, as well as time and money for materials and set up. I use their Virtual Gel Electrophoresis instead.
After reading an overview, students go through the steps to create a DNA blue print. After going through the virtual lab, students might find the article Can DNA Demand a Verdict? interesting to see how gel electrophoresis is used in forensics.