Peptide reconstitution calculator
Enter the amount of peptide in the vial, the volume of bacteriostatic water you add and the amount you want per portion. The calculator returns the concentration, the volume per portion in millilitres and the number of portions per vial. For planning laboratory research only.
5.00 mg/ml concentration
0.050 ml per portion
40 portions per vial
How the calculator works
The calculation has three steps. First the concentration: the peptide in the vial (mg) divided by the volume of bacteriostatic water added (ml) gives mg per ml. Second the volume per portion: the amount you want (converted to mg) divided by the concentration gives the millilitres to take. Third the number of portions: the amount in the vial (in µg) divided by the amount per portion.
Worked example
A 10 mg vial is reconstituted with 2 ml of bacteriostatic water. The concentration is 10 ÷ 2 = 5 mg/ml. A portion of 250 µg (0.25 mg) needs 0.25 ÷ 5 = 0.05 ml. The vial gives 10,000 µg ÷ 250 µg = 40 portions.
What affects accuracy
- Nominal amount and peptide content. The figure on the vial is the nominal amount. The actual peptide content is on the certificate of analysis for the lot; counter-ions and residual moisture make up part of the weight (see peptide content).
- More water, easier measuring. A larger volume gives a lower concentration, so each portion is larger and can be measured more precisely with a graduated pipette.
- Dead volume. A small residue always stays in the equipment. With very small volumes that residue matters more.
- Storage after dissolving. Reconstituted solutions are kept at 2 to 8 °C. If you will not use it all at once, divide it into aliquots.
The terms in more depth: reconstitution and bacteriostatic water. Storage before and after reconstitution: storing lyophilised peptides in the laboratory.
Questions
How much water goes into a vial?
There is no fixed figure. 1 to 3 ml is common for 5 to 10 mg vials. What matters is that each portion can then be measured comfortably.
Does the calculation work for blends such as GLOW or KLOW?
Yes, for the total amount in the vial. The share of each peptide is on its product page; the concentration of each component follows from that share.
Why is the result in millilitres?
Volume is what you measure at the bench. If your equipment is graduated in another unit, convert from the millilitres.
What is the calculator for?
Planning in vitro laboratory work. It does not replace a laboratory protocol and is not intended for human use.
Research use only. All products are supplied exclusively for in vitro laboratory and scientific research, not for human or veterinary use.