What is a lyophilized peptide?

Why peptides are dried

Peptides are chains of amino acids, and in water those chains slowly break down. Water takes part in most of the chemical reactions that wear a peptide away, so removing it makes the compound far more stable. A dry powder is also light, compact and easy to ship, which is why almost every research peptide is supplied this way.

How freeze-drying works

1. Freezing. The peptide solution is frozen solid in the vial.
2. Primary drying. The pressure is lowered and the ice turns directly into vapour without melting, a step called sublimation.
3. Secondary drying. The last traces of bound water are driven off, leaving a dry, porous cake.

What the powder looks like

Most freeze-dried peptide is white or off-white. It may sit as a small mound, a thin film on the glass, or a loose powder that has shifted during shipping. A few milligrams is a very small amount, and some vials look almost empty. That is normal and does not mean anything is missing.

Handling dry vials

Keep the vial sealed until you need it, and keep it cool, dry and out of the light. Before opening or reconstituting it, let the vial come to room temperature so that moisture from the air does not condense on the cold powder.

What comes next

A lyophilized peptide has to be dissolved before it can be measured out for an experiment. That step is called reconstitution, and our post on it describes the usual laboratory routine.

Common questions

Why does one vial look different from the next? The way the cake forms during freeze-drying varies a little from vial to vial, and a difference in appearance on its own is normal.

What if a seal is broken? A cracked glass, a loose cap or a damaged seal means the vial should not be used. Keep the packaging, take a clear photo and write to support@pep-pantry.is with your order number.

Research use only

Pep Pantry products are sold for laboratory research by adults. They are not for human or veterinary use. This article describes laboratory handling only.