MOLBIOTOOLS

MOLBIOTOOLS groups DNA, chemical, buffer, centrifugation and probability tools with separate user guides. Its DNA calculator accepts pasted sequence or plain-text, FASTA and GenBank files. Select DNA/RNA, strand count, linear/circular form and the linear molecule's 5′ terminus before calculating mass or concentration. The guide distinguishes isotope-average nucleotide weights, terminus corrections and nearest-neighbor 260 nm extinction coefficients. Absorbance conversion uses optical path length in cm and a dilution factor; concentration calculations also require the configured sequence's molar mass. The separate dsDNA base-pair calculation uses the guide's stated average 617.9, neglecting sequence composition. The provider says entered data stay in the browser; its separate advertising-cookie policy still applies.