Laboratory fundamentals

What is reconstitution?

Reconstitution is the process of adding a sterile liquid diluent to a lyophilized (freeze-dried) peptide vial to bring it back into solution for use.

What water should be used to reconstitute a peptide?

Bacteriostatic water for injection is the default for multi-dose vials. Sterile saline is preferred for preservative-sensitive contexts (intranasal, single-use). Tap water is never appropriate.

Why does concentration matter?

Concentration determines what dose an injection volume delivers. Two vials with the same peptide mass at different concentrations require different injection volumes to deliver the same dose.

What is bacteriostatic water?

Bacteriostatic water is sterile water containing 0.9% benzyl alcohol as a preservative — enough to inhibit bacterial growth in a multi-dose vial over several weeks of repeated access.

What is sterile technique?

Sterile (aseptic) technique is the set of practices that prevent microorganisms from entering a sterile product between the vial closure and the injection site.

How long does a reconstituted vial last?

Most peptides remain stable for 30 days refrigerated after reconstitution with bacteriostatic water, though specific compounds have shorter or longer stability. Always follow the supplier's beyond-use date.

How should peptides be stored?

Lyophilized vials: refrigerate (2–8 °C) or freeze for long-term. Reconstituted vials: refrigerate. Never store on the refrigerator door or near the freezer compartment.

How do I know if a peptide has degraded?

Visible cloudiness, discoloration, or particulate in a reconstituted vial are signs of degradation. Loss of potency without visible change is also possible — this is why beyond-use dating matters.