If the absorbance reading at 260 nm is 2.545 and the dilution factor is 30, what is the concentration of DNA extracted?

To determine the concentration of DNA extracted from the absorbance reading, the relationship between absorbance and concentration needs to be utilized. At 260 nm, the absorbance of a nucleic acid solution can be used to estimate DNA concentration using the equation:

[ \text{Concentration} (µg/mL) = (\text{Absorbance at 260 nm} \times \text{Dilution factor}) \times 50 ]

In this case, the absorbance reading is 2.545, and the dilution factor is 30.

1. Multiply the absorbance by the dilution factor:

( 2.545 \times 30 = 76.35 )

2. The next step involves multiplying this value by the factor of 50, which is the conversion factor used to correlate absorbance at 260 nm to DNA concentration:

( 76.35 \times 50 = 3817.5 )

Thus, the concentration of DNA extracted is 3817.5 µg/mL, which corresponds to the correct choice. This demonstrates how absorbance readings directly relate to the concentration of DNA in a solution, and highlights the importance of dilution factors in accurate calculations.