Research Guides
Storing and Handling Lyophilised Research Peptides in the Lab
Oct
Lyophilised research peptides keep best sealed, cold, dry and dark, at around -20°C for long term storage or 2°C to 8°C for short periods.
Let a cold vial reach room temperature before opening it, reconstitute gently in a solvent suited to the sequence, then aliquot the solution and avoid repeated freezing and thawing.
Most research peptides are supplied as a lyophilised, or freeze dried, powder. In that form they are relatively stable. Once they leave that state, or are stored badly, they can degrade long before they reach an assay, and the material you test is no longer the material described on the certificate.
Scope: this article covers general laboratory handling practice. It does not describe any effect of any compound, and all Master Biolabs material is supplied for laboratory research use only.
What degrades a peptide
Peptides and proteins break down by a small number of well described routes. Knowing them makes every storage rule below easier to remember.
Hydrolysis
Water breaks peptide bonds over time. This is why moisture is the first thing to control.
Oxidation
Residues such as methionine, cysteine and tryptophan react with oxygen, which air exposure speeds up.
Deamidation
Asparagine and glutamine residues can change chemically, especially in solution and at higher temperatures.
Aggregation
Peptide molecules can clump together, which agitation and repeated freeze and thaw cycles encourage.
When a vial arrives
- Inspect the vial and seal for damage
- Match the batch number on the label to the published certificate of analysis
- Record the date received, batch number and storage location
- Move the vial into cold, dark storage the same day
Lyophilised powder can look like a small pellet, a thin film on the vial wall or a loose cake. Differences in appearance between batches are normal and are not by themselves a sign of a problem.
Storing lyophilised material
- Temperature: around -20°C for long term storage, or 2°C to 8°C for material that will be used within a few weeks.
- Moisture: lyophilised peptides are hygroscopic, so they draw water from the air. Keep vials sealed and consider storing them with a desiccant.
- Light: keep vials in their box or a dark container, particularly sequences known to be light sensitive.
Let a cold vial sit sealed on the bench for 20 to 30 minutes before opening it. Opening it cold draws in warm air, and moisture condenses directly onto the powder.
Reconstitution in the laboratory
The right solvent depends on the peptide sequence and on your protocol, so check the published literature for the compound you are working with. Common choices in research settings include:
- Sterile water for many short, water soluble peptides.
- Bacteriostatic water, sterile water containing 0.9% benzyl alcohol, used where a solution will be drawn from more than once.
- Dilute acetic acid for some basic peptides that dissolve poorly in water.
- A small volume of DMSO, followed by dilution, for strongly hydrophobic sequences where the assay can tolerate it.
Work aseptically. Add solvent slowly down the inside wall of the vial rather than onto the powder, then swirl or roll the vial gently until it dissolves. Avoid vigorous shaking, which can cause foaming and aggregation. Record the volume added and the resulting concentration on the vial and in your notes.
Storing peptides in solution
In solution, a peptide is far less stable than it was as a powder.
- Aliquot the solution into single use portions so you only thaw what you need.
- Avoid freeze and thaw cycles. Frozen aliquots are better than one stock thawed again and again.
- Keep working solutions cold at 2°C to 8°C and use them promptly.
- Limit air exposure for sequences containing methionine, cysteine or tryptophan.
Records that link back to the batch
For every vial, record the batch number, date received, date reconstituted, solvent and volume, concentration and storage conditions. If a result ever looks unusual, you can trace it straight back to a specific batch and its certificate.
Safe handling
Handle research compounds in a suitable laboratory by trained personnel, using standard personal protective equipment such as gloves, a lab coat and eye protection. Dispose of used vials and consumables according to your institution’s procedures.
- Store sealed vials cold, dry and dark
- Warm before opening to stop condensation on the powder
- Choose a solvent suited to the sequence and your protocol
- Reconstitute gently and never shake hard
- Aliquot solutions and avoid repeated freeze and thaw cycles
- Keep every record tied to a batch number
Frequently asked questions
Sealed, cold, dry and dark. Around -20°C suits long term storage, and 2°C to 8°C suits material that will be used within a few weeks.
Opening a cold vial draws in warm air, and moisture condenses onto the powder. Moisture speeds up degradation, so a short wait protects the material.
It is sterile water with 0.9% benzyl alcohol. The preservative limits bacterial growth, so it is used where a solution will be drawn from more than once.
Repeated freeze and thaw cycles can degrade a peptide. Dividing the solution into single use aliquots before freezing avoids the problem.
- Manning MC, Chou DK, Murphy BM, Payne RW, Katayama DS, 2010. Stability of protein pharmaceuticals: an update. Pharmaceutical Research, 27(4), 544 to 575. DOI
- International Council for Harmonisation, 2003. ICH Q1A(R2) Stability Testing of New Drug Substances and Products. View source
- Pamies D, Leist M, Coecke S, et al., 2022. Guidance document on Good Cell and Tissue Culture Practice 2.0 (GCCP 2.0). ALTEX, 39(1), 30 to 70. DOI
All Master Biolabs products are supplied strictly for laboratory research use only. They are not medicines and are not for human or veterinary use. Please read our Research Use Policy before ordering.