Peptide Reconstitution Calculator
Enter the lyophilized amount in your vial, the volume of bacteriostatic water you add, and a target analyte mass. The calculator returns the solution concentration, the aliquot volume in milliliters and microliters, the graduation marks that volume reaches on a U-100 graduated syringe, and how many aliquots a vial yields. For laboratory reconstitution calculations only.
U-100 scale — 100 graduation marks per mL.
For laboratory reconstitution calculations only. Not medical, dosing, or clinical guidance, and not instructions for administration.
How reconstitution math works
Lyophilized peptides ship as a freeze-dried powder and must be dissolved in a diluent — typically bacteriostatic water — before use in research. The resulting concentration is simply the peptide mass divided by the diluent volume: a 5 mg vial reconstituted with 2 mL of bacteriostatic water yields 2.5 mg/mL (2,500 mcg/mL). The volume containing a target analyte mass is that mass divided by the concentration: 250 mcg ÷ 2,500 mcg/mL = 0.1 mL (100 µL), which a pipette measures directly.
Adding more diluent makes pipetting easier (each aliquot is a larger, more precisely measurable volume) while adding less keeps aliquot volumes small. The total peptide in the vial never changes — only the concentration does.
Reading the graduated-syringe scale
Small volumes are often measured on a graduated U-100 syringe, where the barrel is divided into 100 marks per milliliter — so 1 mL reads 100 units, 0.5 mL reads 50, and 0.3 mL reads 30. To find the mark an aliquot reaches, multiply its volume by 100: the 0.1 mL (100 µL) aliquot above reaches the 10-unit mark. The calculator also reports the analyte mass at each mark (here, 25 mcg per unit) so a full scale can be read at a glance. These are volume-measurement figures, not dosing or administration instructions.
Reconstitution & storage quick reference
- Use bacteriostatic water for solutions held over multiple sessions — the 0.9% benzyl alcohol inhibits bacterial growth. Sterile water suits single-use preparation only.
- Direct the diluent stream down the vial wall, not onto the lyophilized cake, and swirl gently — never shake — to preserve peptide integrity.
- Store lyophilized vials at −20°C long-term (2–8°C short-term), protected from light. Reconstituted solutions are typically held at 2–8°C and used within the window appropriate to the compound under study.
- Minimize freeze–thaw cycles; aliquot if a study design requires repeated access.
Peptide calculator — frequently asked questions
Divide the peptide mass in the vial by the volume of bacteriostatic water you add to get the solution concentration, then divide your target analyte mass by that concentration to get the volume to draw. A 5 mg vial reconstituted with 2 mL of bacteriostatic water is 2.5 mg/mL (2,500 mcg/mL), so a 250 mcg aliquot is 0.1 mL (100 µL). The calculator above does this automatically.
There is no single correct volume — the diluent only sets the concentration, not the total peptide in the vial. Adding more bacteriostatic water makes each aliquot a larger, more precisely measurable volume; adding less keeps volumes small. Common choices are 1–3 mL per vial; enter your vial size and diluent volume to see the resulting concentration.
A graduated U-100 syringe is divided into 100 marks per milliliter, so multiply the aliquot volume in mL by 100 to find the unit mark — a 0.1 mL (100 µL) aliquot reaches the 10-unit mark. The calculator reports this for 0.3 mL (30u), 0.5 mL (50u), and 1 mL (100u) graduated syringes. These are volume-measurement figures, not dosing or administration instructions.
It is the analyte mass at each graduation mark of a U-100 syringe for your chosen concentration. At 2,500 mcg/mL on a U-100 scale (100 marks per mL) each unit holds 25 mcg, so the full scale can be read at a glance. It is a measurement reference, not a dose.
Divide the total peptide mass in the vial by your target analyte mass per aliquot. A 5 mg (5,000 mcg) vial divided into 250 mcg aliquots yields about 20 aliquots. The count is independent of how much diluent you add — only the concentration changes.
No. It performs in-vitro laboratory reconstitution math for research-use-only reference standards. It is not medical, dosing, or clinical guidance and is not instructions for administration.
All Eon Research compounds ship lyophilized in multi-vial research kits from our US facility with tracking. This tool and the information above are provided for in-vitro laboratory research calculations only and do not constitute medical, dosing, or clinical guidance.