Ranna's Biology Blog: Candy Electrophoresis Lab

Focus Questions:

We found that our experimental samples did not match the color of all four reference samples. We used yellow m&ms, which was close to the yellow 5 color. The yellow Reese's pieces were similar to the yellow 6 reference dye. The purple skittles did not match the Blue 1 reference dye in any way, and the pink Mike and Ike were slightly similar in color. But the blue reference dye traveled the slowest, behind all the others on the gel. The light pink pigment was much softer and clearer than the bright, thick Red 40 reference dye. It was difficult to compare the bands of each dye because there was an assembly when we ran our gels, and most groups in our class struggled due to the time limitations. Some dyes ran off the gel, while some were still making their way across it. Unfortunately, the experimental error affected our test a lot, because we had to leave the electrical current running through the gel for too long.
The fast green FCF will most likely migrate similarly to the Blue 1 reference dye because they have the exact same structure and chemical composition. The citrus red 2 color is also close to the Red 40 dye because of similar structure, but the chemical composition is slightly different, therefore it may migrate similarly.
Dog food manufacturers might put food dyes into their products because it makes it more appealing the dog, and human. Like the ABC news article by Susana Kim, "11 Food Ingredients Banned Outside the U.S. That We Eat" mentioned, people will only eat something that is good for them if it smells or looks good, regardless of the taste. Food dyes that are not as dangerous are said to be mostly used for the influence of perception, source Michael Pariza mentioned. "Taste, appearance, and smell all go together. You can have the most fantastic, nutritious thing in the world, but if it looks bad and smells bad, you're not going to eat it," he said. All in all, dyes are placed to make the food more desirable.
Natural food dyes that can replace artificial dyes include; red beet juice as an alternative to Red 40, spirulina extract for Blue 1, turmeric powder for Yellow 5, and paprika for Yellow 6. Usually, artificial dyes are used over natural dyes because they last longer, are more vibrant in some cases, don't affect taste/smell, and are much cheaper to have access to.
The level of voltage in the electric current affects the dyes ability to migrate. We were on a time crunch so the voltage and power were on the maximum setting. The higher powered electrical currents made dyes move faster. Another important factor is the size of the dye and how much the wells in the gel were actually filled. The dyes with higher amounts moved slower than those with less, which moved across the gel faster.
The negatively charged dyes are attracted to the positive electrical current, so the dyes are pulled across the gel in the direction of the positive electrode.
The agarose gel acts like a filter, and molecules are separated by size through the pores. Smaller molecules can travel through the gel quickly and with ease, while the opposite is true for larger molecules.
I would expect the molecule with the lowest molecular weight(6000-dalton) to separate the fastest because of its small size. Following, 1,000 and then 2,000 dalton molecules. Last, I would expect the 5,000-dalton molecule, the heaviest and largest of all to be the slowest to separate. In conclusion, the 6,000-dalton molecule would travel the farthest and fastest because of its smaller size, and the 5,000-dalton molecule would travel the slowest, and least amount because of its large size