1. What is Nucleotide Molecular Weight?

The molecular weight (MW) of a nucleotide sequence is the sum of the atomic weights of all atoms in the molecule. It's essential for various molecular biology applications including PCR, sequencing, and oligonucleotide synthesis.

2. How Does the Calculator Work?

The calculator uses the following formula:

Where:

• Nucleotide masses — Standard molecular weights for each base
• Modification mass — Additional mass from 5' or 3' modifications

Explanation: The calculator sums the molecular weights of each nucleotide in the sequence and adds any modification weights if specified.

3. Importance of Molecular Weight Calculation

Details: Knowing the MW is crucial for:

• Calculating molar concentrations
• Designing PCR primers
• Determining synthesis scales
• Estimating melting temperatures

4. Using the Calculator

Tips:

• Enter sequence in 5' to 3' direction
• Only standard bases (A,T,C,G for DNA; A,U,C,G for RNA) are accepted
• Case insensitive (a = A)
• Spaces and numbers are automatically removed

5. Frequently Asked Questions (FAQ)

Q1: Why are DNA and RNA molecular weights different?
A: RNA contains uracil (U) instead of thymine (T) and has an extra hydroxyl group on the 2' carbon of the ribose sugar.

Q2: Does this account for modified bases?
A: No, this calculator only handles standard bases. Special modifications require custom calculations.

Q3: How accurate is this calculation?
A: It uses standard nucleotide molecular weights accurate to two decimal places.

Q4: Does it account for terminal modifications?
A: Yes, you can specify 5' or 3' phosphate modifications.

Q5: Can I calculate MW for mixed DNA/RNA sequences?
A: No, the calculator requires you to specify either DNA or RNA sequence type.