How It Works
This calculator works in 4 steps.
Choose the label basis
Select mass (mg), substance amount (nmol), or activity (U).
Enter content and corrections
Type the labeled amount, the net content percent, and the MW when converting mass to molar.
Enter the target concentration
Type the stock strength in mM, mg/mL, or U/mL.
Read the solvent volume
The calculator returns µL and mL to add to the vial.
The Formula
The formula converts the labeled content to moles or units and divides by the target concentration.
n (nmol) = m (mg) × net % / 100 × 10⁶ / MWV (µL) = n (nmol) / C (mM)V (mL) = U / (U/mL)- m:
- Labeled mass
- net %:
- Net peptide or active content
- MW:
- Molecular weight (g/mol)
- C:
- Target concentration
- U:
- Activity units
A 1 mg peptide vial with MW 1,000 g/mol holds 1,000 nmol. For a 1 mM stock, add 1,000 µL (1 mL) solvent.
Conversion Table
The conversion table converts 6 lyophilized amounts into nmol and solvent volume for a molar stock (100% net content).
| Vial content | MW | Amount | Target | Solvent volume |
|---|---|---|---|---|
| 1 mg | 1,000 g/mol | 1,000 nmol | 1 mM | 1,000 µL |
| 5 mg | 450.5 g/mol | 11,099 nmol | 10 mM | 1,110 µL |
| 1 mg | 5,000 g/mol | 200 nmol | 1 mM | 200 µL |
| 0.1 mg | 25,000 g/mol | 4 nmol | 0.1 mM | 40 µL |
| 10 mg | 300 g/mol | 33,333 nmol | 50 mM | 666.7 µL |
| 2 mg | 1,500 g/mol | 1,333 nmol | 2 mM | 666.7 µL |
What Is the Lyophilized Reagent Reconstitution Calculator?
The Lyophilized Reagent Reconstitution Calculator is a tool that converts the labeled mass, substance amount, or activity of a freeze-dried reagent into the solvent volume for a target molar, mass, or activity concentration. The calculator accepts mg, nmol, and units (U) from the label.
Freeze-dried (lyophilized) peptides, enzymes, and standards often list net content in mixed forms, such as "1 mg peptide, 95% net peptide content" or "500 U enzyme". The calculator applies net content, MW, and activity before solving the volume, and it reminds the user to spin the vial at about 10,000 × g for 1 minute so all powder sits at the bottom.
Common Uses
There are 5 main uses of this calculator.
Synthetic peptides
Researchers make mM peptide stocks from mg vials with net content correction.
Enzymes
Biochemists reconstitute enzymes to set U/mL activity.
Nucleic acid standards
Users make µM stocks from nmol-labeled tubes.
Kit calibrators
Clinical labs reconstitute calibrators to their labeled volume.
Toxin and hormone standards
Analysts reconstitute ng-scale standards for mass spectrometry.