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Laboratory Guidance
Reconstitution Protocol
Standard operating procedure for lyophilised research compounds.
Research Use Only. This protocol is provided for in-vitro laboratory and research use only. It is not intended to guide or facilitate any form of human or veterinary administration. Pepform compounds are not medicines and must not be used on or in any living organism. This document is a laboratory standard operating procedure for qualified researchers.
Overview
Lyophilised (freeze-dried) research compounds are supplied as stable dry powders for long-term storage and transport integrity. Reconstitution is the process of dissolving the lyophilised powder into a suitable solvent to create a research stock solution for in-vitro use.
This protocol covers standard reconstitution procedure, appropriate solvents for different compound classes, storage of prepared solutions, and quality checks. Following this procedure ensures molecular integrity, minimises contamination risk, and produces a consistent, usable stock solution for laboratory assays.
Before You Begin
Allow vials to reach room temperature before opening to prevent moisture condensation on the cold powder. Check the vial is intact and the lyophilised cake is visually undamaged before proceeding. Refer to the compound-specific product page for solubility and storage specifications.
Equipment Required
All equipment used in compound reconstitution should be appropriate for the research application and should not introduce contaminants. The following items are recommended:
Analytical Balance±0.01mg precision · calibratedRequired for concentration calculations
Solvent Selection
Solvent selection depends on the specific compound's chemical properties. Each compound's product page contains solubility specifications. As a general guide, research-grade peptides are most commonly reconstituted using one of the following solvents — selected according to the compound's solubility profile:
Common Solvents for Research Peptides
Sterile Water for Injection (WFI) — suitable for most water-soluble peptides. Use where the compound is fully soluble in aqueous media.
Bacteriostatic Water (BAC Water) — sterile water containing 0.9% benzyl alcohol as a preservative. Extends the usable period of the reconstituted solution in laboratory conditions.
Dimethyl Sulfoxide (DMSO) — for poorly water-soluble compounds. Typically used as a small-volume pre-dissolve step, followed by aqueous dilution.
Acetic Acid (0.1%) — sometimes used for hydrophobic or poorly water-soluble peptide sequences to aid dissolution before aqueous dilution.
Always refer to the compound-specific solubility data. Add solvent slowly to the vial wall — do not agitate or vortex vigorously.
Reconstitution Procedure
Follow this procedure under sterile conditions appropriate to your laboratory setting. All steps should be conducted in a clean, controlled environment using sterile technique.
Allow vial to reach room temperatureRemove the compound vial from −20 °C (or 4 °C) storage and allow to equilibrate to room temperature for 15–30 minutes before opening. This prevents moisture condensation on cold powder which can affect dissolution.
Prepare solvent and equipmentGather all equipment. Inspect the solvent for clarity and check expiry. If using bacteriostatic water, note that it contains benzyl alcohol which inhibits microbial growth in solution. Select the correct syringe volume for your target concentration.
Calculate required solvent volumeDetermine your target stock concentration based on your research assay requirements. For example: 5mg compound + 5ml solvent = 1mg/ml (1000μg/ml) stock solution. Record your calculations and document in your laboratory notebook.Refer to the compound's potency data on the COA — actual peptide content may differ slightly from labelled content (within ±10% specification).
Add solvent slowly to the vialDraw the calculated volume of solvent into a sterile syringe. Insert the needle through the rubber stopper of the compound vial and direct the solvent stream against the inner glass wall — not directly onto the lyophilised powder. This reduces mechanical disruption to the powder.
Allow to dissolve — do not agitateAllow the powder to dissolve at room temperature. Gently swirl the vial every minute or two. Most peptides dissolve within 5–10 minutes. Do not vortex or shake vigorously. If dissolution is slow, allow more time before reconsidering solvent choice.If significant undissolved material remains after 15 minutes, consult solubility data and consider an alternative solvent approach.
Filter sterilise (if required by protocol)For sterility-critical applications, draw the solution through a 0.22μm PES syringe filter into a clean sterile receiving vial. This removes any particulate matter and microbial contaminants. Use a new, sterile filter for each vial.Pepform sterile syringe filters (0.22μm PES) →
Label and documentLabel the reconstituted vial with: compound name, lot number, concentration (mg/ml or μg/ml), solvent used, date of reconstitution, and initials. Record in your laboratory notebook. Verify against your COA batch number.
Store reconstituted solution correctlyStore at 4 °C for short-term use. Avoid repeated freeze-thaw of reconstituted solutions where possible — aliquot into single-use volumes before freezing if long-term storage of the solution is required.
Storage Summary
Form
Temperature
Duration
Notes
Lyophilised powder (unopened)
−20 °C
Up to 24 months
Desiccated; protected from light
Lyophilised powder (opened)
−20 °C or 4 °C
Use promptly
Re-seal immediately; minimise moisture exposure
Reconstituted solution
4 °C
As per compound specification
Do not freeze reconstituted peptide solutions; store refrigerated only
Troubleshooting
Powder not dissolvingAllow more time. Try gently warming the vial in your palm (not above body temperature). Consider a small volume of DMSO to pre-dissolve, then dilute with aqueous buffer. Consult compound-specific solubility data.
Cloudiness or precipitation after dissolutionMay indicate solubility limit has been exceeded. Dilute further with solvent. Alternatively, pH may be outside the compound's stability range — adjust if your protocol permits. Filter through 0.22μm to remove particulates if required.
Colour change or unexpected appearanceSome compounds have characteristic colours (e.g. GHK-Cu is purple/blue). Unexpected discolouration may indicate degradation. Check storage history and solvent compatibility. Do not proceed with degraded material.