Research Reference
Peptide Reconstitution Guide
Reconstitution converts a lyophilized peptide into a working solution at a defined concentration. The process determines every downstream concentration in a study, so it must be documented precisely. This reference describes the standard laboratory procedure.
Choosing the solvent
Bacteriostatic water (sterile water containing 0.9% benzyl alcohol) is the standard solvent for most research peptides because it suppresses microbial growth during the working window. Sterile water is acceptable for shorter-window protocols. A small subset of hydrophobic peptides require dilute acetic acid or DMSO — consult the Certificate of Analysis for the specific lot.
Choosing the reconstitution volume
Volume is selected to produce a working concentration that is convenient for the study protocol. A common approach is to reconstitute a 5 mg vial with 2 mL of bacteriostatic water to yield 2.5 mg/mL. The exact volume depends on the study design — the Dosing Calculator can perform the math for any vial size and target concentration.
Standard procedure
- Allow the lyophilized vial to reach room temperature.
- Wipe the rubber stopper with a 70% isopropyl alcohol swab.
- Draw the chosen volume of bacteriostatic water into a sterile syringe.
- Inject the solvent slowly down the inner wall of the vial — do not inject directly onto the lyophilized cake.
- Gently swirl until fully dissolved. Do not shake; shaking can denature peptide and create foam.
- Label the vial with lot number, reconstitution date, concentration, and discard date.
Concentration verification
Final concentration in mg/mL equals the mass on the label divided by the volume of solvent added. Record this value in the laboratory log. All downstream pipetting volumes derive from it.
Frequently Asked Questions
What is bacteriostatic water?+
Bacteriostatic water is sterile water containing 0.9% benzyl alcohol, an antimicrobial preservative. It is the standard reconstitution solvent for most research peptides because it suppresses microbial growth in the working solution.
How much solvent should be added?+
Volume is chosen to produce a convenient working concentration. A 5 mg vial reconstituted with 2 mL of bacteriostatic water yields 2.5 mg/mL. Use the Dosing Calculator to compute volume for other vial sizes.
Why not shake a reconstituted vial?+
Vigorous shaking can denature the peptide and produce foam. The accepted technique is to inject solvent slowly down the inner wall of the vial and gently swirl until dissolved.