Science Buddies: "Ask an Expert"

I'm creating a gel electrophoresis chamber for my science project. I'm looking to find how many macromolecules are in food dye after being separated in electrophoresis. I am writing my research paper on how gel electrophoresis works. I'm stuck on one thing in particular. What macromolecules are in food coloring? What in food coloring will cause it to be able to separate? Thanks!

Hi Guernsey,

Interesting topic. I would suggest a couple of things to ‘spice’ it up a bit, however. Food dyes are often separated by chromatography, usually paper chromatography, so why don’t you do a comparison of the two separation methods—traditional chromatography vs gel electrophoresis? A science project involves asking a question, stating it as a hypothesis and performing experiments to determine whether the hypothesis is true or false. You should read the Scibuddies description of how to write a good hypothesis for a science project: https://www.sciencebuddies.org/science- ... esis.shtml

What do you mean by ‘macromolecules’ and why are you interested in them specifically. Biological macromolecules would include proteins, DNA and RNA. Nonbiologicals would be synthetic polymers like polypropylene and other plastics. Food colors contain dyes that used to be made from natural ingredients like turmeric but are now more likely to be synthetic organic chemicals. Both types also contain a number of ingredients in addition to the dye and these might or might not be listed on the label. Plant-derived extracts could contain some proteins, carbohydrates or even nucleic acids that hitchhiked along with the dye as it was purified. You could look for these on the gel.

Some people prefer to use ‘natural’ products instead of synthetic ones and there are food colors you can buy that are made from plant and other extracts. You could test the two types of food colors by paper chromatography and by electrophoresis and compare the components.

How were you planning to visualize your macromolecules? Proteins separated by polyacrylamide gel electrophoresis can be stained with a blue dye called Coomassie which you can buy from Carolina Biologicals, http://www.carolina.com/catalog/search- ... SearchForm

The colors that separate on paper chromatography do not need to be stained because they can readily be seen, but if you want to visualize other molecules, you would have to stain them in some way. Here’s some info on paper chromatography and there’s lots more on Google: https://www.sciencebuddies.org/science- ... rces.shtml

Repost on this thread with more details about what specific question you want to ask and we can help you design a great science fair project.

Best wishes,

Sybee