1. What is DNA Extinction Coefficient?

The DNA extinction coefficient (ε) at 260 nm is a measure of how strongly DNA absorbs light at this wavelength. It's used to quantify DNA concentration in solution and is essential for various molecular biology applications.

2. How Does the Calculator Work?

The calculator uses the DNA extinction coefficient equation:

Where:

• \( A \) — Number of adenine bases
• \( C \) — Number of cytosine bases
• \( G \) — Number of guanine bases
• \( T \) — Number of thymine bases

Explanation: Each nucleotide base contributes differently to the overall extinction coefficient due to their unique absorption properties at 260 nm wavelength.

3. Importance of Extinction Coefficient Calculation

Details: Accurate extinction coefficient calculation is crucial for determining DNA concentration, purity assessment, and various molecular biology experiments including PCR, sequencing, and cloning.

4. Using the Calculator

Tips: Enter the number of each nucleotide base in your DNA sequence. All values must be non-negative integers representing the base counts.

5. Frequently Asked Questions (FAQ)

Q1: Why do different bases have different coefficients?
A: Each nucleotide base has unique chemical structure and therefore absorbs light at 260 nm with different efficiency.

Q2: What are typical extinction coefficient values?
A: Typical values range from 5,000 to 50,000 M⁻¹cm⁻¹ depending on the DNA sequence length and composition.

Q3: How is this used to calculate DNA concentration?
A: Concentration = A₂₆₀ / ε, where A₂₆₀ is the absorbance measured at 260 nm.

Q4: Does this work for RNA as well?
A: No, RNA has different extinction coefficients. Use specific RNA extinction coefficient calculators for RNA sequences.

Q5: Are there limitations to this calculation?
A: This assumes standard conditions and may not account for secondary structures or unusual base modifications that affect absorbance.