Food Tests: How To Test For Glucose | Biology Practicals

February 19, 2020 0 By Jose Scott

Hazel: Hi, everyone. I’m super excited to say that I’m with Emilia. Emilia: Hi. Hazel: And Amelia is a science technician at Sancton Wood School in Cambridge, and we’re going to be doing some experiments together. If you want to follow Emilia on Instagram, her handle is, and she does some really cool experiments, so you should go check her out. But I’m super excited because we’re bringing Science with Hazel to the laboratory. In this video, Emilia and I are going to show you how you carry out a test for glucose. It’s a quite straightforward test. Firstly, you need to specify that you need Benedict’s reagent … which is this beautiful blue colour. What you’re then going to do is place a mixture of the Benedict’s reagent and the substance being tested into a boiling tube. So, we have glucose solution in here. So, in this boiling tube, we have a mixture of glucose and the Benedict’s reagent, so you can see it’s a nice blue colour. Crucially, the next stage is, it needs heating, and we’re heating it nice and safely using a water bath. Hazel: Yeah.
Emilia: Yeah. It’s changed. Hazel: Perfect. And as you can see, we have a positive result, which is that the Benedict’s reagent has turned a lovely brick red colour. So in terms of your exam wording, how do we test for glucose? Well, we add the food sample being tested to Benedict’s reagent. You heat it in a water bath, and then a positive results is indicated by a brick red colour. If the Benedict’s had remained blue, we’d have a negative result, so no glucose is present. (music)