Sudan III Test

Dr. Brown explains that Sudan III is used to detect the presence of fat. She goes on to add that this test can be used to identify lipids in biological samples, which can be important for diagnosing conditions like hyperlipidemia.

You take this opportunity to revise the Sudan III test and refer to your lab manual. The experiment uses Sudan III, which is a red dye and olive oil as the fatty substance. 2 mL of oil is added to 2 mL of water in a test tube. 4-5 drops of Sudan III are then added and the mixture is shaken. A red-stained oil layer separates on the surface of the water, which remains uncolored. Fat globules are stained red and are less dense than water, as shown in the image (right: negative test; left: positive test).

Website: https://mrmitchellsbiology.weebly.com/lipid-test.html 

Dr. Brown asks you to reconsider your answer and you think it would also help to watch a video to better understand this test.