Peptide molecular weight & certificate calculator
Work out a peptide's molecular formula and mass from its sequence, see what a certificate's net-content and purity figures say about a vial, and convert milligrams to micromoles. Arithmetic on analytical figures, nothing more.
Molecular formula and mass
Enter a sequence to see its formula and masses.
For the 4 catalog sequences above, the calculated formula matches the one on the product page. Covers linear peptides built from the 20 standard amino acids. D-amino acids weigh the same as their L forms, so enter the ordinary letter. Non-standard residues (Aib, norleucine), cyclization, lipidation and metal complexes aren't modeled; for those, use the molecular weight printed on the certificate or product page. Average mass uses standard atomic weights; monoisotopic mass uses the most abundant isotope of each element.
What the net-content and purity figures say
Enter the label amount, net peptide content and HPLC purity from a certificate.
Net peptide content is the measured mass of peptide in the vial, as distinct from counter-ions, residual water and salts; it is reported, not graded. HPLC purity is the main peak's share of the total peak area: it says how much of the detected material is the target sequence, not how much material is in the vial. The two answer different questions, which is why a certificate reports both. More in How to read a COA, HPLC purity vs. identity, the glossary.
Milligrams to micromoles
Enter a mass and a molecular weight.
Uses the molecular weight of the free peptide. Material supplied as a salt (acetate, TFA) also carries counter-ion mass, which the net-content figure already leaves out.
Every compound we ship carries a signed third-party certificate: verify any lot with the issuing laboratory or browse the COA library. All materials are for in-vitro laboratory research use only, not for human or veterinary use.
