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  1. How has the gel changed?
    (there are bubbles at the electrodes, the gel has softened, the food coloring has spread into the gel)
  2. Did the coloring spread out evenly in all directions?
    (No. The color broke up into connected smears that spread varying distances from the well)
  3. Did the food coloring change shades?
    (Yes - The green separated out into regions of blue and yellow. The yellow traveled the furthest.)
  4. Did the different food colors separate into the same bands? (No - each color separated into its own smear of component colors.)

Think About It

Molecules of DNA have an overall negative charge. If you were to perform electrophoresis on DNA, at which side of the well would you observe the formation of DNA bands? Why? (On the positive side of the well since opposite charges attract.)

When examining the separation bands of DNA, you discover that the smaller fragments of DNA travel the greatest distance from the well. Why? (Smaller size particles make fewer collisions with the molecules that form the gel matrix. With fewer collisions, their movement is less affected than the migration of larger (more frequently colliding) particles.)


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