Final answer:
To determine the concentration of the original DNA sample, we use the absorbance at 260 nm and the formula C = A / (ε * l), where C is the concentration, A is the absorbance, ε is the molar absorptivity constant, and l is the path length. Plugging in the values, we find the concentration to be 1.63 µg/µL.
Step-by-step explanation:
To determine the concentration of the original DNA sample, we first need to know the absorbance of the diluted solution. The question provides the absorbance at 260 nm, which is 0.326. We also know the volume of the diluted sample is 1000 microliters (950 microliters of water + 50 microliters of DNA).
Using the formula C = A / (ε * l), where C is the concentration, A is the absorbance, ε is the molar absorptivity constant, and l is the path length, we can solve for the concentration.
The molar absorptivity constant for double-stranded DNA at 260 nm is 0.020 ng/µL. The path length is typically 1 cm (10 mm) for a spectrophotometer.
Let's plug in the values:
- C = 0.326 / (0.020 * 10)
- C = 0.326 / 0.20
- C = 1.63 µg/µL
Therefore, the concentration of the original DNA sample is 1.63 µg/µL.