Percent agarose = grams/100 ml dH2O. For example:
    0.8% agarose gel = 0.8 g of agarose powder in 100 mL of buffer.
    (always make gel with running buffer, never with water)
 

Melt agarose on a hotplate or in the microwave. Use a stirbar. Stop it when it just starts to boil, do not let it come to a rolling boil. Make sure the hot solution is completely clear. Especially watch out for "lenses" or small pieces of unmelted agarose that reflect light.

Seal frame with tape (midigel and maxigel) or use gel casting tray (minigel and Bio-Rad). Carefully set in the comb.

Do not pour agarose into the frame when it is too hot. It will warp the plastic. Use the "baby bottle" test.

Pour in one even motion. Watch the thickness of the gel on the side of the frame. Immediately after pouring, check carefully for bubbles, especially around the comb.

TBE (Tris-Borate-EDTA) buffer stock = 10X. You must dilute to 1X working concentration. For one liter (1000 mL), add 100 mL of 10X to 900 mL of dH2O Mix thoroughly before pouring into frame.

When gel is solid (opaque, not clear), take off tape or pop out of casting tray. Put gel into gel box. Remove comb in one smooth upward motion. Gel will resist the comb moving.

Add 1X TBE buffer to just cover the wells.

Load gel, cover apparatus, and make sure electrodes are attached correctly before starting your gel.  Can't remember how to position the electrodes?  Always remember, RUN TO THE RED!!