You extracted a sample of DNA and analyzed it using a Nanodrop spectrophotometer. You recorded the following absorbances and then corrected them to produce the following values:

Question

A260 = 0.80

A280 = 0.75

Calculate the quality of DNA in the sample using these corrected absorbance(s). Report your answer to two decimal places (e.g., 1.00, 1.11, etc.) and DO NOT include units.

Be sure that your work:

provides the A260 value
provides the A280 value
identifies the equation that you used to solve the problem,
identifies which numbers you substituted for which variables in the equation,
exhibits all the necessary steps needed to show the math used to solve this problem and provide an answer
Hint: An equation "equates" two entities. If you do not include two things separated by an "=", then you have not written an equation -- you will have simply written a mathematical operation.

Answer 1

To assess the quality of the DNA in your sample, we can use the A260/A280 ratio, which helps indicate the purity of DNA. Pure DNA typically has an A260/A280 ratio of around 1.8.

Step 1: Identify the A260 and A280 values:

• A260 = 0.80
• A280 = 0.75

Step 2: Write the equation:

The equation for calculating the A260/A280 ratio is:

\[ \text{A260/A280 ratio} = \frac{A260}{A280} \]

Step 3: Substitute the values into the equation:

Now we substitute the values into the equation:

\[ \text{A260/A280 ratio} = \frac{0.80}{0.75} \]

Step 4: Perform the calculation:

To calculate the A260/A280 ratio, we perform the division:

\[ \text{A260/A280 ratio} = \frac{0.80}{0.75} = 1.066666667 \]

Step 5: Round the answer:

We need to report our answer to two decimal places.

Thus, when rounded:

\[ \text{A260/A280 ratio} = 1.07 \]

Final Answer:

1.07