Science Buddies: "Ask an Expert"

How would you be able to construct a hypothesis regarding the food colouring dye samples?

Like how would you be able to make a scientific guess on which food colouring dye would migrate the furthest? I have researched and I know that different colours mean that the molecules the samples are made up of are different, but I don't know the scientific evidence to back it up, like if a certain colour would have smaller molecules.

The only hypothesis I can come up with is that smaller molecule fragments travel farther through the gel than larger molecules, but I don't know how to prove that through my results, and that is common knowledge for gel electrophoresis.

Please help!!

[Administrator note: project: https://www.sciencebuddies.org/science- ... ifying-dna ]

Hi!

Thanks for your question regarding this project.

You have a strong hypothesis regarding how far the molecules of different food colors will travel in the gel. To back up your hypothesis, you could do a little bit of research on the molecular weights of the different color food dyes you plan to use for the experiment -- ultimately, as you said in your post, migration through the gel relies on the molecular weight of the compounds in the samples (i.e., the food dyes). From there, you would be able to hypothesize which food dye would travel farthest based on its molecular weight.

Remember, a hypothesis is an educated guess based on what you think will happen, but, as you mentioned, it is always important to find literature to back your hypotheses.

Hope this helps!
--Brandi