1. What is Oligonucleotide Molecular Weight?

The molecular weight of an oligonucleotide is the sum of the atomic masses of all atoms in the molecule. It's essential for determining concentrations, synthesis scales, and experimental conditions in molecular biology.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• Each nucleotide contributes its molecular weight
• Phosphate groups between nucleotides add 79.0 g/mol each
• One water molecule (18.015 g/mol) is added for the complete oligo

Explanation: The calculation accounts for the backbone and terminal groups in addition to the nucleotide bases.

3. Importance of Molecular Weight Calculation

Details: Accurate molecular weight is crucial for preparing solutions with precise concentrations, calculating synthesis yields, and designing experiments.

4. Using the Calculator

Tips: Enter the oligonucleotide sequence (A,T,C,G for DNA or A,U,C,G for RNA). The sequence should contain only valid characters for the selected type.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between DNA and RNA weights?
A: RNA nucleotides are slightly heavier due to the extra hydroxyl group at the 2' position of the ribose sugar.

Q2: Does this account for modified bases?
A: No, this calculator only handles standard bases. Modified bases require special calculations.

Q3: How accurate is this calculation?
A: It's accurate for standard oligonucleotides. For precise work, consider isotopic distribution.

Q4: Does this include 5' phosphate or 3' modifications?
A: No, this calculates for standard oligonucleotides without terminal modifications.

Q5: Can I calculate for both single-stranded and double-stranded?
A: This calculates single-stranded MW. For double-stranded, multiply by 2 and subtract any overhangs.