Electrophoresis equipment is available in many districts, though the school may not have its own equipment. Some districts pool money to buy electrophoresis equipments, others have access through traveling van programs, while others borrow the equipment from nearby universities or colleges. Your electrophoresis equipment may vary. Check the manufactures instructions for specifics for your set up.

#	Item	#	Item
6-8	10-20 uL capillary tube pipettors	3-5 g	agarose
15	glass capillary tubes for pipettors	300 - 400 mL	1X TBE buffer for gels
6-8	gel electrophoresis boxes	6 - 8 L	1X TBE buffer for tanks *
3-4	power supply	5 mL	loading dye
6-8	plastic staining trays	1 - 2 L	0.025% methylene blue *
1	microwave or hot plates	6-8	100 mL graduated cylinders
6-8	125 or 250 mL flasks

Recipes

Concentration Standards

Order from a biotechnology catelogue or contact a molecular biology laboratory.

Loading Dye for DNA

0.25 g bromophenol blue
0.25 g xylene cyanol
50.0 g sucrose
1 mL 1 M Tris (pH 8.0)

1. Wear gloves and a lab coat.
2. Dissolve in 60 mL of distilled water.
3. Add distilled water to bring final volume to 100 mL.
   

1% Methylene Blue

0.5 g methylene blue
50 mL distilled water

1. Wear gloves and a lab coat.
2. Store at room temperature indefinitely.
   

0.025% Methylene Blue

10 mL 1% methylene blue
390 mL distilled water

1. Wear gloves and a lab coat.
2. Store at room temperature indefinitely.
3. After you have stained your gel and DNA, collect and reuse the dye.
   
   

10X TBE Buffer

1 g NaOH
108 g Tris base
55 g boric acid
7.4 g EDTA (disodium salt)

1. Dissolve in 700 mL distilled water.
2. Stir to dissolve. Use a magnetic bar.
3. Add distilled water to bring final volume to 1 L.
   

• This is the stock solution.
• Dilute to 1X TBE before using the buffer in gels or for electrophoresis.
  

1X TBE Buffer

100 mL 10X TBE
900 mL distilled water

1. Mix well.
2. Save the TBE buffer after running your gel; it can be reused.
   

0.8% Agarose Gel

An 0.8% agarose gel means that there are 0.8 grams of agarose per 100 mL of buffer. The amount of agarose you will add, depends upon the size of the gel. The mini-gels generally need between 30-50 mL of solution per gel. Check your Electrophoresis Chamber Instruction Manual for specifics on your model. It won't hurt to have gels that are too thick, it just wastes money and chemicals.

	for a 35 mL gel	for a 50 mL gel
agarose	0.28 g	0.4 g
1X TBE buffer	35 mL	50 mL

1. Mix in 125 or 250 mL flask.
2. Loosely plug the top with paper towel.
3. Microwave on high for approximately 2 minutes.
4. Swirl to mix.
5. Reheat until agarose has completely dissolved (no floating particles or "lens" are visible).
6. Cool to 55 C before pouring gel solution into the casting tray.
   

• Do not let the solution boil over in the microwave.
• Use gloves. The glass flasks get hot!
• The gel solution can be remelted in the microwave if it solidifies in the flask.
• Gels can be made 1-2 days ahead of time and store in the refrigerator wrapped in plastic wrap.
  
  
  
  

Science Education Connection Department of Biochemistry The University of Arizona Tuesday, January 14, 1997 warder@u.arizona.edu http://biology.arizona.edu/sciconn/lessons/vuturo/ All contents copyright © 1997. All rights reserved.