Lyophilization Fundamentals: Why Peptides Are Freeze-Dried

Lyophilization removes water from a frozen peptide solution under vacuum, leaving a porous solid that can be stored for years and rapidly reconstituted on demand.

The three phases

1. Freezing — solute and solvent separate as ice crystals form
2. Primary drying — ice sublimates directly to vapor under vacuum
3. Secondary drying — bound water desorbs from the amorphous matrix

What it means for handling

Lyophilized cake is hygroscopic. Always equilibrate vials to room temperature before opening to prevent atmospheric moisture from condensing onto cold powder.