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.



Your Answer:

Answers

GPT-4o mini
To calculate the expected absorbance of a DNA solution, you can use the relationship between DNA concentration and absorbance at 260 nm, known as the Beer-Lambert Law. For nucleic acids, specifically DNA, the absorbance (A) can be estimated using the following formula:

\[ A = \epsilon \cdot c \cdot l \]

Where:
- \( \epsilon \) (molar absorptivity) for DNA is approximately 50 ng/mL per absorbance unit.
- \( c \) is the concentration of DNA in ng/mL (for DNA), and we typically convert ng/μL to ng/mL by multiplying by 1000.
- \( l \) is the path length of the cuvette, usually 1 cm.

1. **Convert the concentration**:
\[ 34.00 \, \text{ng/μL} = 34.00 \times 1000 \, \text{ng/mL} = 34000 \, \text{ng/mL} \]

2. **Now calculate the absorbance**:
\[ A = \frac{34.00 \, \text{ng/mL}}{50 \, \text{ng/mL}} = 0.68 \]

Therefore, the expected absorbance of the solution of DNA at a concentration of 34.00 ng/μL is **0.68**.