Credits and licences

Last updated 2026-10-11

Our own code

The tools and page layouts are written for this site. The pages make no requests to other servers.

The calculators use published constants and textbook formulas, typed into our own code (no third-party tables or libraries are copied):

Standard atomic weights: IUPAC Commission on Isotopic Abundances and Atomic Weights (abridged values).
Avogadro constant and the molar gas constant: exact SI values (2019 redefinition) and CODATA.
Amino-acid residue masses: calculated from the residue formulas with the standard atomic weights.
Protein extinction coefficients: Pace et al., Protein Science 4 (1995) 2411.
Oligonucleotide extinction coefficients: nearest-neighbour values of Cantor, Warshaw and Shapiro, Biopolymers 9 (1970) 1059.
Dilution, molarity, titration, buffer (Henderson–Hasselbalch), stress–strain and centrifuge (RCF) formulas: standard textbook equations, with standard gravity g = 9.80665 m/s².
Plate and flask growth areas: Thermo Fisher Gibco “Useful numbers for cell culture” table. Water density: Tanaka et al. (2001) equation.

None at present. If we add any library, font or data set, it will be listed here with its licence and a link (data/credits.json, rendered below).