1. What is Nucleic Acid Molecular Weight?

The molecular weight (MW) of a nucleic acid is the sum of the atomic weights of all atoms in the molecule. For oligonucleotides, it's typically calculated as the sum of the molecular weights of the individual nucleotides.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• \( MW \) — Molecular weight in g/mol
• \( base\_masses \) — Array of individual nucleotide masses in g/mol

Explanation: The calculator simply sums up all the individual base masses you provide to give the total molecular weight.

3. Importance of Molecular Weight Calculation

Details: Knowing the molecular weight is essential for preparing solutions with specific molar concentrations, for electrophoresis, and for various molecular biology applications.

4. Using the Calculator

Tips: Enter the masses of individual bases separated by commas (e.g., "329.2, 345.2, 313.2"). All values must be valid positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What are typical molecular weights for DNA bases?
A: dA: 313.2, dT: 304.2, dC: 289.2, dG: 329.2 g/mol (as free acids without 5' phosphate).

Q2: How do I account for modifications?
A: Include the modified base's exact mass in your input. Many modifications add significant mass to the standard bases.

Q3: Does this account for terminal phosphates?
A: No, you need to add 79.0 g/mol for 5' monophosphate or 159.0 g/mol for 5' triphosphate separately.

Q4: What about RNA versus DNA?
A: RNA bases have slightly different masses (e.g., U instead of T is 306.2 g/mol). Use the appropriate values for your nucleic acid type.

Q5: How accurate is this calculation?
A: It's theoretically exact if you input exact masses, but real samples may vary due to isotopes and impurities.