A protein solution has an absorbance of 0.5 at 280 nm. If the path length is 1 cm and the molar extinction coefficient is 10,000 M^-1 cm^-1, what is the concentration of the protein?

• A. 0.05 M
• B. 0.00005 M
• C. 0.005 M
• D. 0.5 M

Answer: (B)