Storing peptides: fridge, freezer, light and moisture

• Check that the vial is sealed and undamaged.
• Compare the lot number on the vial with the certificate on Lab results.
• Then put the vials somewhere cool. Freeze-dried powder tolerates a short period at room temperature during shipping.

The product page says "2–8 °C recommended": that is the short-term rule. For longer storage the freezer is better.

• Short term: in the fridge, at 2–8 °C.
• Long term: in the freezer, at −20 °C or colder.
• For years: at −80 °C, if your lab has it.
• Always dry and dark: in the box or a closed container, optionally with a sachet of desiccant (silica gel).

Freeze-dried powder attracts moisture. If you open a vial straight from the fridge or freezer, moisture from the air condenses on the cold powder, which speeds up breakdown. Let a vial reach room temperature first, and close it tightly after use.

Take only the vial you need out of the freezer, so the others do not keep warming up and cooling down.

Some amino acids, such as tryptophan, tyrosine and methionine, are sensitive to light or oxidation. Keep vials in the dark, in the box or a light-tight container, and do not leave a solution in the sun or under a lamp.

• Keep the solution in the fridge (2–8 °C), on an inner shelf and not in the door.
• Do not freeze a solution: ice crystals can damage the peptide structure.
• Use a solution in bac water within about 28 days; use a solution in sterile water without preservative in one go.
• Stop using a solution that turns cloudy or yellow, or in which you see particles.

Write the date, the solvent, the concentration and the lot number on every dissolved vial, so you know later exactly what is in it and how old it is. Work out the concentration with the peptide calculator; dissolving itself is covered in Dissolving peptides.

Dispose of leftovers and empty vials according to your laboratory's waste rules.

Do peptides need to go in the fridge?

As a powder, in the fridge (2–8 °C) for the short term and in the freezer (−20 °C or colder) for longer. A dissolved vial always in the fridge.

Can a dissolved peptide go in the freezer?

No. Ice crystals can damage the peptide structure. Keep a solution in the fridge.

How long does a peptide keep?

As a freeze-dried powder, stored dry and cold, a long time: much longer in the freezer than in the fridge, and for years at −80 °C. In solution far shorter; you use a solution in bac water within about 28 days.

Is a peptide spoiled if it was warm for a few days?

Freeze-dried powder tolerates a short period at room temperature, such as during shipping. Put it somewhere cool afterwards. That does not apply to a solution: it belongs in the fridge.

• View Bac water in the shop