Laboratory tools for peptide handling
Small, transparent calculators for the arithmetic that surrounds peptide handling. Each one shows its formula, works only on the numbers you enter, and stores nothing.
Reconstitution calculator
Vial fill and diluent volume to mg/mL, µg/µL and µM — with purity correction, aliquot count and a C1V1 dilution step.
Cost per mg peptide calculator
Compare up to three quotations on cost per milligram of target peptide, accounting for fill weight, peptide content and purity.
HPLC dilution calculator
Stock to working concentration, mass injected on column, and a serial dilution series — with the arithmetic shown.
What these tools do, and what they do not
Every calculation here is arithmetic on values you supply: mass, volume, purity and molecular weight. The tools do not model a protocol, do not suggest how much material to use in an experiment, and do not substitute for a validated laboratory method or a certificate of analysis. Where a result depends on an assumption — that the fill is pure peptide, that added solvent equals final volume — the page states the assumption next to the number.
Why the inputs matter more than the calculator
Most concentration errors we see in incoming QC questions are not arithmetic errors. They come from reading a nominal fill as peptide mass, from a purity figure quoted without its method, or from a certificate whose molecular weight refers to the salt while the weighing refers to the fill. A calculator cannot detect any of those; the COA reading guide and the article on counter-ion forms can.
Method notes
- Concentration: mg/mL = peptide mass (mg) ÷ final volume (mL). 1 mg/mL equals 1 µg/µL.
- Purity correction: peptide mass = fill mass × assayed purity or peptide content ÷ 100.
- Molarity: mol/L = concentration in g/L ÷ molecular weight in g/mol; 1 mg/mL equals 1 g/L.
- Dilution: C1V1 = C2V2, solved for the stock volume.
Related reading
- Reconstitution practice — solvent choice and technique
- Storage and handling — solution stability and freeze–thaw
- Cost per mg calculator — normalising quotations across fills and salt forms
- HPLC dilution calculator — stock dilution, injection mass and serial series
- Testing methods — where purity and content values come from
- All knowledge guides