Biuret Reagent is an aqueous solution of biuret (allophanamide) treated with cupric sulfate and sodium hydroxide. In the presence of protein, this blue solution will change color to pink-purple.
Protein Test - Biuret solution
- To a test tube, add 40 drops of liquid to be tested.
- If testing more than one liquid, label each test tube with a marker.
- Add 3 drops of Biuret reagent solution to each test tube. Shake gently to mix.
- Note any color change. Proteins will turn solution pink or purple.