Question
What is the expected absorbance of a solution of DNA that has a concentration of 34.00 ng DNA/μL?
Report your answer to two decimal places.
Report your answer to two decimal places.
Answers
GPT-4o mini
To determine the expected absorbance of a solution of DNA at a concentration of 34.00 ng/μL, we can use the absorbance formula based on the Beer-Lambert Law.
The absorbance (A) can be calculated using the following formula:
\[
A = \epsilon \cdot c \cdot l
\]
Where:
- \( A \) = Absorbance
- \( \epsilon \) = Molar absorptivity (L/(mol·cm))
- \( c \) = Concentration (mol/L)
- \( l \) = Path length (cm)
For nucleic acids, a common value for the molar absorptivity (\( \epsilon \)) at 260 nm is approximately 0.020 (optical density per ng/μL).
1. Convert the concentration from ng/μL to μg/mL:
- 34.00 ng/μL = 34.00 μg/mL
2. Use the typical conversion that 1 μg/mL of DNA corresponds to an absorbance of approximately 0.020 at 260 nm. Thus:
\[
A = \text{Concentration (μg/mL)} \times 0.020
\]
3. Substitute the given concentration:
\[
A = 34.00 \, \text{μg/mL} \times 0.020 = 0.68
\]
Thus, the expected absorbance of the solution is **0.68**.
The absorbance (A) can be calculated using the following formula:
\[
A = \epsilon \cdot c \cdot l
\]
Where:
- \( A \) = Absorbance
- \( \epsilon \) = Molar absorptivity (L/(mol·cm))
- \( c \) = Concentration (mol/L)
- \( l \) = Path length (cm)
For nucleic acids, a common value for the molar absorptivity (\( \epsilon \)) at 260 nm is approximately 0.020 (optical density per ng/μL).
1. Convert the concentration from ng/μL to μg/mL:
- 34.00 ng/μL = 34.00 μg/mL
2. Use the typical conversion that 1 μg/mL of DNA corresponds to an absorbance of approximately 0.020 at 260 nm. Thus:
\[
A = \text{Concentration (μg/mL)} \times 0.020
\]
3. Substitute the given concentration:
\[
A = 34.00 \, \text{μg/mL} \times 0.020 = 0.68
\]
Thus, the expected absorbance of the solution is **0.68**.