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Star Republic: Guide for Biologists

Protein concentration --- Modified Lowry

1. Modified Lowry is less 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, 1% SDS) 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 650 nm.