Compute molecular weight for DNA sequences as single- or double-stranded, linear or circular molecules.
Paste one or more raw or FASTA-formatted sequences (limit 200,000,000 characters). Degenerate bases are supported.
Treat sequences as single- or double-stranded molecules.
Select whether molecules are linear or have been ligated to form circles.
Paste one or more DNA sequences in FASTA format or as raw text. The tool supports IUPAC degenerate bases (R, Y, S, W, K, M, B, D, H, V, N) and can handle up to 200 million characters.
Choose "Single-stranded" for single-stranded DNA or "Double-stranded" to calculate the combined weight of both strands (including the reverse complement).
Select "Linear" for linear DNA fragments or "Circular" for plasmids and circular molecules. Circular molecules have reduced weight due to the absence of terminal hydroxyl groups.
Click execute to calculate molecular weights. Results show exact weights for non-degenerate sequences or weight ranges when degenerate bases are present.
Degenerate bases expand to the lightest and heaviest possibilities, producing a molecular weight range when ambiguity is present.
Circular molecules omit the terminal hydroxyl group, reducing the reported weight by 17.01 Da relative to linear strands.
Double-stranded calculations combine both strands, using the reverse-complement sequence to honor degeneracy on the second strand.
Each strand includes a 5′ monophosphate (17.01 Da), matching the assumptions of the legacy Sequence Manipulation Suite implementation.