Research Guide
Preparing peptide stock solutions.
A concise reference on how to reconstitute a lyophilized peptide for laboratory research use. Terminology and technique only — no dosing or human-use guidance.
Reconstitution steps
Read First
Research-use context only.
This guide describes preparation of peptide stock solutions for in-vitro and laboratory research workflows. It does not describe preparation for injection, human use or any therapeutic application. See the full Research-Use Disclaimer.
Materials
What you need.
Source
Lyophilized peptide
The sealed vial as received. Check the label for compound, mg quantity and batch reference. Do not open until ready to reconstitute.
Diluent
Bacteriostatic water (BAC)
Sterile water with 0.9% benzyl alcohol, appropriate for short-term research storage. Select diluent based on the peptide’s solubility profile; acidic or citrate-buffered water for specific compounds.
Transfer
Sterile syringe
Use a sterile syringe to draw and inject the diluent. Choose a volume that matches your target stock concentration.
Workspace
Clean bench / laminar flow
Prepare in a clean, draft-controlled environment. Wipe the vial stopper with isopropanol before puncturing.
Procedure
Step-by-step.
Step 1
Equilibrate
Let the sealed vial come to room temperature. Reconstitution into cold glass can cause condensation and affect accuracy.
Step 2
Calculate volume
Decide your target stock concentration. For a 5 mg vial reconstituted to 1 mg/mL, add 5 mL diluent. Record the exact volume added for downstream calculations.
Step 3
Add diluent slowly
Inject the diluent slowly down the inner wall of the vial. Do not inject directly onto the lyophilized cake — the force can shear peptide bonds in some compounds.
Step 4
Dissolve gently
Swirl the vial gently. Do not shake. Let the peptide dissolve fully (typically 30 to 90 seconds) before using. Solution should be clear.
Step 5
Label
Label the reconstituted vial with compound, concentration, date reconstituted and batch reference. Essential for traceability.
Step 6
Store properly
Store reconstituted peptide under the conditions described in the Storage & Handling Guide.
Watch Out For
Common pitfalls.
Vigorous shaking
Shaking can denature peptides and introduce air bubbles. Always swirl or invert gently.
Wrong diluent
Some peptides require acidic water or specific buffered solutions. Check compound-specific solubility before reconstituting.
Temperature shock
Adding cold diluent to a warm vial (or vice versa) can cause partial precipitation. Equilibrate both first.
No labelling
An unlabelled reconstituted vial is a traceability break. Label immediately, not later.
Research library
Read the methodology in depth.
Long-form research-frame guide on reconstitution methodology — bacteriostatic vs acetic acid water, dilution math, multi-puncture handling, storage windows, common errors. Plus the COA verification step that comes before reconstitution.
Pillar guide · 11 min
Reconstitution methodology — full guide
The complete research-handling literature deep-dive: diluent comparison table, dilution math, multi-puncture stability, storage windows.
Methodology · 10 min
Verify identity first — how to read a COA
Before you reconstitute, verify the peptide is what the label says. HPLC, mass-spectrometry, water content, lot traceability.
Tool
Reconstitution calculator
Vial mg + target concentration → diluent volume in mL. Skip the math, get the number.