Contents
Electrophoresis of Dyes (activity)
- Prepare a 1% agarose gel by adding 60ml Tris-Borate-EDTA buffer (TBE) to 0.6g agarose in an erlenmeyer flask
- Place flask in microwave or on heat until agarose is melted
- stop periodically and swirl solution and do not permit to boil over
- Assemble the casting tray by blocking the ends with tape or plastic gaskets
- Place the comb into the center of the casting tray
- You may place the casting trays inside a refrigerator and pour the solution into the tray
- Wait until the gel is solidified
- Carefully separate the gaskets from the tray
- Remove the comb and place the casting tray into an electrophoresis chamber
- Cover the gel with TBE buffer
- Using a micropipettor, load 40-50μl dye samples sequentially into the wells
- Cover the electrophoresis chamber with the lid and ensure good contact between electrodes
- It is conventional that the POSITIVE side of the tank is nearest to you
- With the POSITIVE side nearest to you, load the samples from left to right
- Set the power supply to 100-120V and press the Run button (you should see bubbles at each electrode) and allow to run for at least 40 minutes
- After 40 minutes, stop the current and remove the gel in casting tray
- Place tray on a white background and document your gel
Activity Follow-up
- What colors were the dyes originally before loading into the wells?
- How many separate bands of dye are in each well following the run?
- What does it mean that there are multiple bands in a lane? What does it mean that there is only one band in a lane?
- What does the length of migration illustrate to us about the properties of the dye molecules?
- In which direction did the dye molecules migrate? What does the direction of migration indicate about the analytes?
- Are there lanes where there are multiple bands of the SAME color?
