Expressing concentration in units of μg/mL or mg/mL are common in biochemistry, where accurate molecular weights of biomolecules are not always known. The plot below is the standard curve of a Bradford assay, a colorimetric method used to determine the concentration of protein. Assume you have 5.00 mL of a protein-containing solution. You take 0.0500 mL of your protein solution, add 0.950 mL of Bradford reagent, and measure the absorbance of the mixture. If the mixture has an absorbance of 0.546, what concentration of protein is present in your original solution?

Question

Expressing concentration in units of μg/mL or mg/mL are common in biochemistry, where accurate molecular weights of biomolecules are not always known.  The plot below is the standard curve of a Bradford assay, a colorimetric method used to determine the concentration of protein.  Assume you have 5.00 mL of a protein-containing solution.  You take 0.0500 mL of your protein solution, add 0.950 mL of Bradford reagent, and measure the absorbance of the mixture.  If the mixture has an absorbance of 0.546, what concentration of protein is present in your original solution?

I thought that I was supposed to use the equation given by the line of best fit (y=0.0119x), but that answer was incorrect (45.9M). Please help if you can! Thank you!

Libbie · Answer

Oh! I forgot to include the r^2 value (if that is needed) r^2=.9917

Anonymous · Answer

Nevermind :) I figured it out! Thank you though!