Protein concetation at 280 nm - (Sep/09/2015 )

Any nice and simple protocol to determine the protein concentation at 280 nm if the extinction coefficient is known..

Measure A280...dilute sample if necessary to ensure sample reading is between 0.1 and 0.5.  

Never trust an absorbance reading above 1.0.

Exception: nano-drop specs can read much higher absorbances. Dyanamic range is ~1-100 for nanodrops.

Then, Beer's law.