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Research use only · Not for human or veterinary use · 21+

Guide

How to Store Lyophilized Research Peptides

Most research peptides arrive as a lyophilized (freeze-dried) powder in a sealed vial. In that dry form they are fairly stable, but heat, moisture, light and air all slowly break them down. This guide covers how laboratories usually store sealed lyophilized material. It does not cover peptides once they are in solution.

Temperature: -20 °C, 2-8 °C or room temperature

Manufacturers agree on the broad picture. Sigma-Aldrich recommends storing lyophilized peptides at -20 °C or colder for the long term. Bachem recommends below -15 °C, says colder is better for very long storage, and notes that a refrigerator at about 4 °C is fine for short-term storage.

  • -20 °C or colderLong-term storage. The standard condition for sealed vials kept for months. Bachem notes that lower temperatures are preferred for very long storage.
  • 2-8 °CShort-term storage. A laboratory refrigerator is acceptable for sealed vials that will be handled again soon.
  • Room temperatureTransit. Sealed lyophilized vials are routinely shipped at ambient temperature and hold up for days to weeks. Move them to cold storage when they arrive.

If a supplier prints a specific storage condition on the label, follow the label. It reflects that product and that lot.

Shipping and temperature excursions

Room-temperature shipping is normal for sealed lyophilized peptides. Sigma-Aldrich describes them as stable for days to weeks at ambient temperature. A few days in transit is not a problem in itself. What matters more is what happens after delivery: put the vials into cold storage promptly.

Moisture, desiccant and condensation

Moisture is the main enemy of a dry peptide. Bachem points out that peptides tend to be hygroscopic, so they pull water out of the air. Absorbed water lowers the peptide content of the powder by weight and can reduce stability.

  • Keep vials tightly closed, and keep them in a sealed container with desiccant if you can.
  • Let a cold vial reach room temperature before you open it, ideally inside a desiccator. Opening it cold lets moisture condense on the powder.
  • Open the vial only for as long as needed, then reseal it tightly.

Light, air and oxidation-prone residues

Sigma-Aldrich recommends keeping lyophilized peptides away from bright light. Oxygen in the air matters too, especially for certain amino acids. Methionine (Met), cysteine (Cys) and tryptophan (Trp) are prone to oxidation, which is a well-documented degradation pathway for peptides and proteins. Bachem also lists asparagine (Asn) and glutamine (Gln) among the residues that limit shelf life.

If a sequence contains these residues, the basics count for more. Store it cold, dark and dry, and keep the vial sealed between handling steps. You can find each product’s sequence on its page in our research peptide catalog.

To read a lab report, see our guide to peptide purity, net peptide content and identity. For the label itself, see what “research use only” means.

Sources

For laboratory research use only. Not for human or veterinary use.

Peptide storage

Common questions

Sealed lyophilized peptides are commonly shipped at room temperature and stay stable for days to weeks. For short-term storage a refrigerator at 2-8 °C is common, and for long-term storage manufacturers recommend -20 °C or colder.

There is no single shelf life. It depends on the sequence and how the vial is kept. Peptides containing Asn, Gln, Met, Cys or Trp have more limited shelf lives, so follow the storage condition and any retest date on the label.

Peptide powders tend to absorb water. Opening a cold vial lets moisture from the air condense on the powder, which reduces peptide content and can lower stability. Let the sealed vial warm up first, ideally in a desiccator.