One can determine the concentration of DNA by reading optical density (OD) at 260 nm. 0.050 mg/mL of DNA gives an absorbance of 1.0 OD260 units. Suppose one makes a series of dilutions as follows: 10 uL of stock solution into 500 uL buffer, then place 10 uL of this diluted solution into 1 mL of buffer, and find OD260 = 0.25. What is the DNA concentration in the stock solution?
