Tool

Peptide reconstitution calculator

Milligrams in the vial, millilitres of water, concentration out. Add the molecular weight and you get molarity too. Every pepuro product has a preset page with both filled in.

Concentration
2.5 mg/mL
2.5 µg/µL · 2500 µg/mL
Molar
- mM
Enter a molecular weight

Concentration = peptide mass ÷ diluent volume. Molarity = (mg/mL ÷ g/mol) × 1000. Research use only.

How to use it

  • Type the milligrams on the vial label. The chips on a product's own calculator page are the sizes we sell.
  • Type the millilitres of water you will add, or switch modes and type the concentration you want instead.
  • Read the result. mg/mL and µg/µL are the same number. Add a molecular weight for mM and µM.

What the numbers mean

Concentration is mass divided by volume, and nothing here is cleverer than that. The reason to use a calculator is the molar column: the same 5 mg is 3.5 micromoles of a small peptide and 1 micromole of a large one, and that difference decides everything if your work is in molar units. Molecular weights for every product are on the Specifications tab and preset on the product's calculator page below.

The handling around the numbers

The calculator does the arithmetic. The technique is in how to reconstitute a lyophilized peptide.

Common questions

How do I calculate peptide concentration after reconstitution?+

Divide the milligrams of peptide in the vial by the millilitres of water you added. 5 mg in 2 mL is 2.5 mg/mL. The amount of peptide never changes; only the concentration does.

How much bacteriostatic water should I add to a peptide vial?+

Whatever volume lands on a concentration that is easy to measure for your work. Use the second mode of the calculator: type the concentration you want and it gives the volume. For a 5 mg vial, 2.5 mg/mL needs 2 mL.

What is the molar concentration of a reconstituted peptide?+

Concentration in mg/mL divided by the molecular weight in g/mol, times 1,000, gives millimolar. 2.5 mg/mL of a 1,419 g/mol peptide is 1.76 mM. Every product's molecular weight is on its Specifications tab and preset on its calculator page.

Does this work for any peptide?+

Yes. Type any mass and any molecular weight. The preset pages are for pepuro products, with our vial sizes and the weight from the Specifications tab already entered.

Presets for every pepuro peptide

Our vial sizes and the molecular weight already filled in.

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