RNA Molar Extinction Coefficient Calculator

RNA Molar Extinction Coefficient Equation:

\[ \varepsilon = 40 \times (A + G) + 33 \times (C + T) \text{ (at 260 nm)} \]

Adenine Count (A):

count

Guanine Count (G):

count

Cytosine Count (C):

count

Thymine Count (T):

count

RNA Molar Extinction Coefficient (ε):

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1. What is RNA Molar Extinction Coefficient?

The RNA molar extinction coefficient (ε) is a measure of how strongly RNA molecules absorb light at 260 nm wavelength. It is used to quantify RNA concentration in solution and is essential for molecular biology applications.

2. How Does the Calculator Work?

The calculator uses the RNA molar extinction coefficient equation:

\[ \varepsilon = 40 \times (A + G) + 33 \times (C + T) \text{ (at 260 nm)} \]

Where:

\( \varepsilon \) — Molar extinction coefficient (L/mol·cm)
\( A \) — Adenine nucleotide count
\( G \) — Guanine nucleotide count
\( C \) — Cytosine nucleotide count
\( T \) — Thymine nucleotide count

Explanation: The equation accounts for the different extinction coefficients of individual nucleotides, with purines (A and G) having higher coefficients than pyrimidines (C and T).

3. Importance of RNA Extinction Coefficient

Details: Accurate determination of RNA extinction coefficient is crucial for quantifying RNA concentration using spectrophotometry, which is essential for RNA sequencing, gene expression studies, and various molecular biology experiments.

4. Using the Calculator

Tips: Enter the count of each nucleotide in your RNA sequence. All values must be non-negative integers. The calculator will compute the molar extinction coefficient at 260 nm.

5. Frequently Asked Questions (FAQ)

Q1: Why are the coefficients different for each nucleotide?
A: Different nucleotides have different chemical structures and therefore absorb light at 260 nm with varying intensities. Purines generally have higher extinction coefficients than pyrimidines.

Q2: Can this calculator be used for DNA sequences?
A: No, this calculator is specifically for RNA. DNA has different extinction coefficients and requires a separate calculation.

Q3: How accurate is this calculation?
A: This provides a theoretical estimate based on nucleotide composition. Actual measurements may vary slightly due to sequence context and secondary structure.

Q4: What is the typical range for RNA extinction coefficients?
A: For most RNA molecules, extinction coefficients range from 20,000 to 100,000 L/mol·cm depending on length and nucleotide composition.

Q5: How is this used to calculate RNA concentration?
A: Concentration = (Absorbance at 260 nm) / (Extinction coefficient × Path length), where path length is typically 1 cm.