Reconstitution & concentration calculator
Work out stock concentration, aliquot volume and the number of aliquots per vial for in-vitro work. All values are in laboratory units.
Formulas
- Concentration (mg/mL = µg/µL) = vial mass (mg) ÷ diluent volume (mL)
- Aliquot volume (µL) = target mass (µg) ÷ concentration (µg/µL)
- Aliquots per vial = diluent volume (µL) ÷ aliquot volume (µL), rounded down
Choosing a diluent and handling the stock: see the laboratory reconstitution guide.
Frequently asked questions
How is peptide concentration calculated?
Concentration (mg/mL) = peptide mass in the vial (mg) ÷ diluent volume (mL). Because 1 mg/mL equals 1 µg/µL, a 5 mg vial reconstituted in 2 mL gives 2.5 mg/mL, or 2.5 µg per µL.
How do I work out the aliquot volume?
Aliquot volume (µL) = target mass per aliquot (µg) ÷ concentration (µg/µL). For 250 µg aliquots from a 2.5 µg/µL stock, each aliquot is 100 µL.
Why aliquot reconstituted stock?
Repeated freeze–thaw cycles and repeated opening of the stock vial degrade peptides and risk contamination. Splitting stock into single-use aliquots in low-protein-binding tubes and freezing them keeps each experiment on equivalent material.
Does the calculator account for peptide content?
Not automatically. Lyophilised peptides contain counter-ions and water, so net peptide content can be below the nominal vial mass. For quantitative work, use the measured mass from the batch certificate as the vial mass.