Build a Gel Electro- phoresis Apparatus Lab III-6 EQUIPMEnT and MaTERIaLs You'll need the following items to complete this lab session. (The standard kit for this book, available from www.thehomescientist.com, includes the items listed in the first group.) MATERIALS FROM kIT · Leads, alligator clip (2) · Ruler MATERIALS YOU PROVIDE · Aluminum foil · Batteries, 9V transistor (5, 7, or 9) · Gel casting comb materials (see text) · Marking pen (Sharpie or similar) · Plastic containers (see text) · Scissors · Tape (electrical or masking) BaCkGRoUnd There's a time-honored custom in science: we scientists build our own apparatus. Not always, of course, nor even most of the time. Nowadays, anyway. Sometimes it's cheaper, easier, and faster just to buy what we need. But when we need something to complete an experiment and that something isn't available or we don't have the budget to buy it, we make do. If that involves designing and building a piece of equipment, so be it. For the following lab session, we needed a gel electrophoresis apparatus and power supply, and we didn't feel like spending $300 or $400 to buy one. So we designed and built our own, at a total cost of about $10. Lab III-6 : Build a Gel Electrophoresis Apparatus 143