Calculate the molecular weight of a DNA molecule from its length and strandedness.
A single nucleotide averages 330 daltons, so a double-stranded base pair is about 650. Converting nanograms to picomoles requires the molecular weight, which is why the same mass of a short primer contains far more molecules than of a long plasmid. Molar rather than mass equivalence matters in ligation and PCR, so this conversion is needed for every reaction setup.
DNA Molecular Weight
Double stranded: MW ≈ 650 × bp; single stranded: MW ≈ 330 × bases + 79
Double stranded: MW ≈ 650 × bp; single stranded: MW ≈ 330 × bases + 79 A single nucleotide averages 330 daltons, so a double-stranded base pair is about 650. Converting nanograms to picomoles requires the molecular weight, which is why the same mass of a short primer contains far more molecules than of a long plasmid.
Molar rather than mass equivalence matters in ligation and PCR, so this conversion is needed for every reaction setup.
This calculator takes 3 inputs: Length in bases or base pairs, Strandedness, Quantity available. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.