Testing for Protein - the Biuret test

Aim: To test if a sample of food contains protein.

Equipment: Test Tube, sodium hydroxide (NaOH0, copper sulfate (CuSO), food sample.

Method:
1. Place about 2 mL of the sample into a test tube and add 5 drops of sodium hydroxide.
2. Add 5 drops of copper sulfate
3. Shake the test tube gently from side to side.

Results:




Conclusion: The solution went from blue to purple because the protein was present.