Materials

Freezer Storage Box (These are seasonal in Mississippi, but are very cheap. I get them at WalMart).

Stainless steel or NiChrome wire (you can buy a 40' spool of nichrome wire from Carolina Biological Supply for about $10.00)
Lantern Battery
Banana plugs and banana jacks (Radio Shack sells these for $2.60 per pack)

Hook up wire (about $5.60 at Radio Shack)

Drill with 5/16 inch bit
Eyedropper or pasteur pipette
A thick toothed comb about 10cm long
Paper clips
Masking tape

Reagents

Agarose

(The more you buy, the cheaper it is per use. 25g or agarose costs about $25.00 from a supplier like US biochemicals).

(Carolina Biological Supply sells 150ml of 20X TBE for 11.00. The problem here is that it does not have a very long shelf life. US Biochemicals sells a pack of 6 bottles of powdered TBE that each make 200 ml of 10X solutions for about $21.00. To make the liquid TBE, you make add deionized or distilled water till the volume comes to 200ml. The powder can last for years).

Sucrose (table sugar)

Drill two holes on one side of the freezer box as shown.

Attach the nichrome wire or stainless steel wire to the banana jacks as follows:.

Cut a length of wire 5 - 6 inches long. Make a hook in the end. Insert the hook through the large rectangular hole in the attachment point of the banana jack.

Loop the hook through the small hole at the base of the attachment popint in the banana jack as shown. The end of the hook should be on the concave surface of the attachment point of the banana jack.

Use a pair of pliers to squeeze the hook and attachment point of the banana jack.

To make the banana plugs, cut a piece of hook up wire to the desired length. Strip about 2cm of insulation from the end of the wire. Unscrew the plastic sleeve from the banana plug. remove the steel sleeve from the banana plug and run the bare end of the hookup wire through the center of the plug until about 5mm protrudes, as shown:

bend the wire back, as shwon, and screw the steel sleeve back onto the plug. Replace the plastic sleeve and the banana plug is complete. You will need 2 banana plugs and 2 banana jacks as shown below:

Line up the banana plug with the hole in the freezer box as shown:

Bend the nichrome wire out as shown:

This step is necessary to get the wires to the proper depth when you insert the plug int the freezer box.

Insert the banana jacks into the holes in the freezer box as shown.

Bend the wire downwards so that the wire runs along the bottom of the freezer box and tighten the nut to secure the plug. Repeat for the other plug to get a final electrophoresis chamber as shown below:

Making the Gel Tray
 

Cut the bottom out of a freezer box as shown. Cut about 1" from each end of the freezer box bottom as shown.

Score the freezer box bottom with sandpaper as shown. This is necessary to get the gel to adhere to the freezer box bottom.

Tape around the freezer box with masking tape bottom as shown.

First tape around the edge as shown:

Then tape around the edge such that more tape is on the bottom of the tray, as shown:

Clip two large paper clips onto the edge of the electrophoresis chamber as shown:

Assemble a comb apparatus with a ruler, two large paper clips and a large toothed comb as shown (I used a comb I had available, any large toothed comb will work fine, even if you have to remove some teeth to get decent spacing (teeth should be at least 2mm apart).

Place the comb apparatus over the gel tray, about 1cm from one end (which will be the negative end in your electrophoresis chamber).

Make sure the teeth of the comb do not touch the bottom of the gel tray. A good working distance is about 2mm between the bottom of a comb tooth and the bottom of the gel tray. You are ready to pour a gel into the gel tray.

It doesn't make any difference how the gel tray is placed in the chamber to make the gel, but when you run the gel, the wells formed by the comb MUST be at the negative end.

You now have an electrophoresis chamber, and are ready to pour a gel. I use 30ml of gel solution. You can use more, and get deeper wells, but agarose is your most expensive reagent, and the more solution you use, the more agarose you use.

Make up 100 ml of 0.5X TBE per gel. If you start with a 10X solution, you would add 5 ml of 10X TBE to 95 ml of distilled or deionized water.

Place 30 ml of TBE into another container. Add 0.24 grams of agarose (to make a 0.8% gel...100g/100 ml = 100% gel) to the TBE and boil the solution. Cool the solution to about 50 degrees centigrade and pour the solution into the gel tray as shown. If the gel temperature is too high, it will melt the adhesive on the masking tape, causing massive leaking. The agarose will not gel until it reaches a temperature of about 37 degrees centigrade.

When the gel has solidified, remove the comb, remove the masking tape and place the gel into the electrophoresis. There should be a gap between the gel and the side of the electrophoresis chamber to corrrespond with the position of the wires in the chamber.

NOTE: The gel is very slippery, and you need to handle it with some care once you remove the tape. This is the most expensive part of your system.

Pour TBE buffer into the electrophoresis chamber until the gel is submerged, with about 2mm of buffer over the gel.

The food coloring can be added to the wells after the buffer is added. The food coloring will be easier to load onto the gels if you increase the density of the food coloring solution. Increasing the density of the solution will cause it to fall to the bottom of the well more easily. The easiest way to add density to the solution is to add sucrose, up to a maximum of about 20% (weight to volume, 20% would be 20 grams of sucrose in 100 ml of liquid). 5% sucorse should work well.

Use the pasteur pipette or the eyedropper to transfer the food coloring solution into the gel. Do not put the end of the eyedropper or the pasteur pipette into the well. Break the surface tension of the buffer over the well with the end of the eyedropper or pipette, the slowly add the solution. It will sink into the well. If it overflows, it is no problem.

Once the gel is loaded, attach the lead from the banana plug at the end of the gels with the wells to the negative end of the lantern battery ands the other lead to the positive end of the lantern battery, as shown. The dyes are negatively charged molecules, and thus will move from the negative pole to the positive pole in the electrophoresis chamber.

It will take several hours for the dyes to move sufficiently into the gel.