Laboratory reference
Stock solution concentration
Concentration is mass divided by volume. The correction most calculators leave out is peptide content: net vial weight includes counterion, residual water and salts, so label claim alone overstates how much peptide is actually present. Enter the content figure from the lot certificate to see both.
The stated mass on the vial.
How much solvent is added. Choose the volume that gives the concentration your work requires.
From the certificate. Net vial weight includes counterion, residual water and salts, so this is below 100% for most material. Leave blank to calculate from label claim alone.
From the compound record. Required only for molar concentration.
Concentration
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Molar concentration
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Enter molecular weight to calculate.
Concentration is mass divided by volume — there is no correct volume independent of the concentration a given experiment requires. For quantitative work, apply peptide content from the lot certificate before calculating molarity; using label claim alone overstates the figure by whatever fraction of the vial is counterion, water and salts. All values are calculated in your browser and nothing is transmitted.