Compute molecular weight for DNA sequences as single- or double-stranded, linear or circular molecules.
Nucleotide weights (monophosphate form): dAMP = 313.21, dTMP = 304.20, dCMP = 289.18, dGMP = 329.21 g/mol.
ssDNA linear: Σ(nt weights) + 18.02 (terminal H₂O)
ssDNA circular: Σ(nt weights) — no free termini
dsDNA linear: Σ(strand1) + Σ(complement) + 36.04
dsDNA circular: Σ(strand1) + Σ(complement)
For degenerate IUPAC bases, a MW range (min–max) is reported.