The most accurate method of determining protein concentration
is acid hydrolysis followed by amino acid analysis. Most other
methods are sensitive to the amino acid composition of the protein
and absolute concentrations cannot be obtained. The procedure
of Lowry et. al. is no exception, but its sensitivity is moderately
constant from protein to protein, and it has been so widely used.
MATERIALS AND SOLUTIONS
Solution A: 2% (w/v) Na2CO3 in distilled water
Solution B: 1% (w/v) CuS04-5H2O in distilled water
Solution C: 2% (w/v) Sodium Potassium Titrate in distilled water
Prepare immediately before use by mixing Solution A: Solution
B: Solution C = 100: 1: 1 (v/v/v).