1. Lowry is sensitive to detergent.

2. Make fresh solution C by mixing 25 ml of solution A (2% Na₂CO₂, 0.02% NaK tatrate (NaKC₄H₄O₆• 4H₂O), 0.1 M NaOH) with 1 ml of solution B (0.5% CuSO₄).

3. Make a dilution of BSA (0-20 mg) in ddH₂O for the standard curve.

4. Add 1 ml of the solution C to tubes containing samples (1-10 ml) and BSA standards. Mix and let stand for 15 minutes at room temperature.

5. Add 0.1 ml of 1 M Folin and mix immediately. Let stand for 30 minutes at room temperature.

6. Read the absorbance at 595 nm.