The Biuret Test

Aim:

To test if a sample of food contains protein

Equipment:

Test tube
Sodium Hydroxide
Copper sulfate
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:

The egg (the top photo) and the milk (Bottom photo) both went purple, though they were different shades of purple

Conclusion:

Both our milk and our egg went purple, it did take a lot more copper sulfate and sodium hydroxide than it was meant to but we got there. The purple means there is protein present in the sample.