Science Buddies: "Ask an Expert"

my project is- forensic science: building your own tool for identifying dna, and it involved gel electrofloresis.
-What is the purpose of using the buffer solution?
-about how long should i keep the gel electrofloresis kit running on the batteries?
we tested food dye for the gel electrofloresis.
-why did the red food dye not have any other bands of color while the blue and green dyes did?
Also, i am having trouble identifying the control in the experiment.
- Is the control the amount of time we let the gel electrofloresis kit run?
-What are some key ideas needed for the conclusion of this experiment?

Hi Audrey,

I think these answers will help you - let me know if you have further questions

Tonya

-What is the purpose of using the buffer solution? This keeps the gel moist and the pH correct. It also allows the current to run through it, then through the gel and samples.

-about how long should i keep the gel electrofloresis kit running on the batteries? Until you see the bands of color moving - just as long as you want, to see good separation. If you keep running it a long itme, the color bands will run right off the edge of the gel, into the buffer!
we tested food dye for the gel electrofloresis.

-why did the red food dye not have any other bands of color while the blue and green dyes did? - the red dye is made of one molecule but the blue and green have more than one molecule, so the different molecules run at different places on the gel.

Also, i am having trouble identifying the control in the experiment. This depends on your hypothesis. What was your hypothesis?
- Is the control the amount of time we let the gel electrofloresis kit run? no.
-What are some key ideas needed for the conclusion of this experiment? the dyes are made of different molecules. Some dyes are made of more than one molecule. The electricity runs the gel. The point of electrophoresis is to separate things based on size, using electricity as power.

Our hypothesis is: The green dye will have more bands than the other colors and it will travel a farther distance than the others because it's not a primary color like red and blue are.
What would the control be?
Thanks!
-Audrey and Leila

The purpose of a control is to make sure your equipment and experiment is working consistently. Ie...your gel is set enough for you to add the dyes, your buffer is conducting the current. So, you could use anything as a control that you have previously tested and you know works in this experiment. So for example. If you know that the orange dye separates into 2 colors but now you want to test the green, red and blue, you could run the orange alongside to make sure that it acts the same way it did the first time so that you know your gel/power etc is working. Hope that makes sense.

Good luck with your project!
Katie

Thanks Katie!