pack 5

Question 1

How does the A260/A280 ratio indicate DNA purity?

Answer 1

The A260/A280 ratio measures protein contamination, with pure DNA having a ratio of ~1.8.

Question 2

What are the acceptable values for the A260/A280 ratio, and what do they signify?

Answer 2

Ratios of 1.8–2.0 indicate pure DNA, while lower values suggest protein contamination.

Question 3

Why is it necessary to blank the spectrophotometer with a blanking solution before measuring DNA concentration?

Answer 3

To account for background absorbance and ensure accurate readings.

Question 4

What does an A260/A280 ratio below 1.7 indicate about your DNA sample?

Answer 4

The sample is contaminated with proteins.

Question 5

What steps should be taken to clean the Nano-Drop before and after measuring DNA concentration?

Answer 5

Clean the Nano-Drop pedestal with distilled water and lint-free wipes before and after measurements.

Question 6

How much DNA is typically extracted from one buccal swab?

Answer 6

Approximately 2–5 μg of DNA is typically extracted.