The concentration of the unknown sample can directly be calculated as follows:

Therefore, the concentration of the protein in the given sample = 10.597 μg/μl = 10.6 mg/ml

Notes:

1. The Coomassie Blue G250 precipitates out of the solution with time. Bradford reagent should therefore be filtered through Whatman no. 1 filter paper before use.
   
   
2. The dye has preferential binding to lysines and arginines in the proteins but does not bind to free lysine and arginine.
   
   
3. The dye does not bind to the peptides smaller than about 3 kDa; Bradford assay, therefore, is not suitable for small peptides.
   
   
4. Quartz (silica) cuvettes should not be used for Bradford assay as Coomassie Blue G250 binds to silica. Disposable polystyrene cuvettes should be used for the assay.
   
   
5. UV/Visible spectrophotometer should be switched on at least 30 min before use.