Using Biuret Solution to Quantitatively Measure Proteins

[jen333]

hi all!
I was just thinking about organic compound indicators, and biuret solution for proteins crossed my mind. I know that it can be used to qualitatively tell the presence of proteins (peptide linkages) with a colour change. But is there a way that biuret solution can be used to take quantitative measurements? ie) spectrophotometry, or is the reaction exothermic allowing a temperature measurement (not quite sure)
Hope to receive some thoughts! thx!

 

[bross7]

Just did a quick search and while the papers I pulled up were somewhat old, mostly 70s/80s, Bieuret can be used with spectrophotometry. The intensity of the colour change is proportional to the amount of protein present.

 

[iansmith]

In my old lab, we used biuret reagent to measure protein concentration of a solution rather than the bradfort reagent. You measure the change in colour using a spectrophotometere. I think the wavelength is 450 nm.

However, the biuret reagent may not be as sensitive as the bradfort, but I'm 100% sure.