Science Buddies: "Ask an Expert"

I am doing the experiment on: "I Love Ice Cream But It Doesn't Like Me"Understanding Lactose Intolerance. When I added the lactase drops to whole milk, skim milk and 2% milk my glucose strip results came out negative showing no glucose . I added 1 drop at a time up to 7 drops and I used varying amounts of milk from 2 tsp to 8 tsp. We did our controled substance test with water and glucose tablets and the strips worked correctly. Why doesn't the glucose strips show glucose readings in the milk after the drops were put in... what am I doing wrong? Thanks for your help!

Hi,

I think you are doing this project:

https://www.sciencebuddies.org/science- ... p031.shtml

Here are some questions that may help identify the problem. Please answer these if you can; some questions may require using materials you don't have readily available, but answer as many as you can.

1. Were you using glucose strips for urinalysis or for blood?
2. Do the test strips work if you add the milk to the glucose tablets? (check for interference)
3. Do the test strips work with commercially available lactose-free milk (which should contain lactose that has been hydrolyzed to glucose and galactose).
4. How long did you incubate the lactose pills or drops with the milk sample? What was the temperature?

Donna Hardy