qualitative test for protein (biuret test)

• 1 - add some milk to a test tuBe labelled A
• 2 - Into a second tube add water and label B
• 3 - to each test tube add a few mls of copper sulfate and a few drops of sodium hydroxide
• results - the solution in test tube A changes colour from blue to violet and the solution in test tube B stays blue
• conclusion - copper sulfate and sodium hydroxide change colour from blue to violet in the presence of protein