How to Reconstitute Lyophilized Peptides

Lyophilized (freeze-dried) peptides arrive as a stable powder and are prepared for laboratory use by adding a diluent. This reference covers the standard bench technique. It is laboratory guidance only — not instructions for administration of any kind.

1 · Choose the diluent

Bacteriostatic water (0.9% benzyl alcohol) is the standard choice for multi-draw laboratory preparations because the preservative suppresses microbial growth across repeated vial entries, supporting a working window of several weeks refrigerated. Sterile water without preservative is appropriate only for single-session use. Some sequences prefer other vehicles (e.g. acetic acid buffers for poorly soluble peptides) — consult the compound's literature.

2 · Volumes and math

The concentration you produce is simply vial content ÷ diluent volume: 10 mg reconstituted with 2 mL yields 5 mg/mL. Choose a volume that makes your target draws easy to measure — our reconstitution calculator does the arithmetic (concentration, draw volume, draws per vial) from any three inputs.

3 · Technique

1. Let the vial reach room temperature; wipe the septum with an alcohol swab.
2. Draw the diluent and introduce it slowly down the vial wall, never jetting directly onto the powder cake — peptides are shear-sensitive.
3. Swirl gently to dissolve. Do not shake. Some sequences take several minutes to clear.
4. Label the vial with concentration and preparation date immediately.

4 · Storage after reconstitution

Refrigerate reconstituted solutions at 2–8 °C, protected from light. With bacteriostatic water, plan around a conservative multi-week working window; discard any solution that turns cloudy or discolors. See the storage reference for the full table.