Dispose of EtBr to glass containers marked for that purpose. Sunlight will beakdown EtBr and may be used to decontaminate stocks. For use, keep EtBr stocks out of the light or renew them by adding EtBr when they get weak. You will need 40 ml of buffer for the BioRad minigel apparatus. You will need an additional 400 ml buffer to run the gel.
Tape ends of gel holder and insert comb.
Make sure that there is a paper width of space between the comb and the bottom of the gel tray and that the comb is level. Make sure the gel holder is also level. Combine in 125 ml flask. Cover top of flask with plastic wrap and punch a small hole in the top. Swirl after each heating.