On Saturday March 29th Mariola Kulawiec and Lawrence Own led HiveBio’s first Electrophoresis class. Four eager students learned about gel electrophoresis using the artificial colors in candies as a bright (and sticky) example of how this technique can be used in chemistry and biology.
Lawrence kicked things off with a brief presentation on the theory behind gel electrophoresis and how it’s used to test properties of DNA, RNA and proteins in biological experiments. He then explained to participants what they will be doing in the lab. Step one: use isopropyl alcohol (rubbing alcohol) to extract the coloring agents from various candies. Step two: Separate the colors using gel electrophoresis!
Our students first had to design their experiment. There were many candies to choose from, but only room on the gel for each person to test a select number of samples. How to choose? Compare single colors across candy types? Make a rainbow? Go for your favorite flavors?
As students set up their candies for extraction, Mariola went over how to keep a record of their experiment using a handout, and emphasized the importance of labeling. In fact, everybody in the room who had worked in a lab before agreed on the importance of having everything labeled clearly. Lawrence explained how to make an agarose gel, and supervised while students prepared one of their own.
During preparation, the candies were soaking in alcohol, but it seemed like the extraction was going very slowly, if at all. What could be the problem? Were the candies used not very well suited to the experiment? Did they need more mixing? Was there a difference between shaking the sample cups and using a pipette to run the alcohol over the candies? What about confectioner’s wax; could the candies be coated? What would happen if the M&Ms were crushed; would the alcohol extract colored compounds from the chocolate?
As often happens in science, one experiment sparked the ideas for many others.
After a brief adventure with a leaky gel tray, students broke out the micro-pipettes and began making standards from commercial food coloring. Working with tiny volumes of food coloring was good practice for handling the extractions.
Loading the gel for electrophoresis requires a steady hand.
And then, it was time for the big challenge – loading the gel! There was one sample too many, and a brief paper-rock-scissors competition ensued to see who would leave out one of their food coloring standards. Loading the gel correctly was a test of lab notebook record-keeping, steady hands, spatial awareness, and tube labeling. During the process a few of the small tubes fell through the rack, but thanks to accurate labeling, no samples were lost!
After some waiting, chatting, and ducking out of the lab to eat some of the untested candies, the gel was done!
Despite challenges and set-backs, a good time was had by all. The class generated some great discussion about results, future experiments and troubleshooting experimental methods for the next round of Candy Electrophoresis! Join us next time!
Veenadhari Kollipara explains gel electrophoresis to friends and family
Mariola and Lawrence both work for Invention Evaluator.
Mariola is also the founder of Witty Scientists (facebook.com/WittyScientists).
Photos and Correspondence by Christine Lloyd