Science Buddies: "Ask an Expert"

Hello!

Our project is about Sucrose, Glucose, and Fructose, and the testing of those sugars in different foods. We used glucose test strips to test the amount of glucose in a controlled percentage of sugar(4%. 2%. 1%, 0.5%, etc...). After some time, some of the strips started to decolorize towards the outer rims, and we decided to laminate them in hopes of preserving the colors tested. However, after the lamination, the colors turned green to a 1% color except for the 0% strip, which stayed its neutral color. We were wondering why and how the strips changed color in reaction to heat, and why they had started to decolorize.

Thank you!
-Micaela, Samantha, Karena, and Michelle

Micaela, Samantha, Karena, and Michelle,

If your glucose test strips are anything like the pH and Nitrate strips that I use, they probably change color as they dry out. I do not know exactly why this happens (and I could not find any good answers online) but for the purpose of having a good visual aid you may want to take a picture of the test strips after the product recommend incubation time.

Figuring our which conditions cause longterm differences in test strip color could be the a future science fair project...

Cheers,
Emily

Hi Micaela, Samantha, Karena, and Michelle,

Emily has already given you some great advice in response to your question. If you decide to repeat your experiment or do a similar one in the future, a great way to preserve your test colors is to take digital photographs of your test strips in full lighting and the same conditions, and use the photos to create a digital color reference card that you can laminate for future use. If you or a friend is good with Photoshop, you can create a really nice reference for comparing your data.

I hope this helps. Please post again (in this same thread) if you have any more questions.

Heather