Why Research
Peptides Are
Lyophilised
Lyophilisation — freeze-drying — removes water from a peptide by sublimation under vacuum, leaving a dry cake or powder. Peptides degrade far faster in solution than in a dry state, so lyophilisation is what gives a research peptide a workable shelf life.
The problem lyophilisation solves
Peptides are not stable in water. In solution they are subject to several degradation pathways at once: hydrolysis of the peptide bond, oxidation of susceptible residues such as methionine and cysteine, deamidation of asparagine and glutamine, and physical aggregation where molecules associate irreversibly with one another.
Every one of those processes requires or is accelerated by water. A peptide left in solution at room temperature can lose meaningful integrity over days. The same peptide, dry and cold, can remain stable for a long period. Removing the water is therefore the single most effective intervention available.
How freeze-drying works
Lyophilisation exploits sublimation — the transition of a solid directly to a vapour without passing through a liquid phase. It proceeds in three stages:
- Freezing. The solution is cooled until the water forms ice crystals, separating the water from the peptide.
- Primary drying. Pressure is reduced under vacuum and a small amount of heat is applied. The ice sublimes directly to vapour and is drawn away, removing the bulk of the water.
- Secondary drying. The temperature is raised further to drive off residual water still bound to the peptide itself.
What remains is a porous cake or powder occupying roughly the shape of the original frozen volume. The porosity matters — it is what allows the material to redissolve readily when a solvent is later introduced.
Why the cake sometimes looks different
The physical appearance of a lyophilised cake varies with the conditions under which it was dried and with the quantity of material present. A cake may be a firm disc, a loose powder, or a thin film on the wall of the vial. Small quantities — a few milligrams in a vial — can be almost invisible.
Movement in transit can also break a cake into powder, or leave it displaced up the side of the vial. Appearance alone is a weak indicator of integrity; the analytical report for the batch is the meaningful record, which is why a certificate of analysis matters more than what the vial looks like.
Storage of lyophilised material
Lyophilised peptides are generally stored refrigerated, sealed, and protected from light. Cold slows the residual degradation pathways further; keeping the vial sealed prevents the hygroscopic cake from drawing moisture out of the air, which would reintroduce the very problem lyophilisation solved.
Once a lyophilised compound is returned to solution, the stability clock restarts. The material is in water again, and all of the degradation pathways described above resume. Solutions are accordingly far less stable than the dry material they came from.
Storage, handling and disposal in a research setting are the responsibility of the purchaser. We do not provide protocols, dosing guidance or usage instructions of any kind.
Frequently Asked Questions
Lyophilised means freeze-dried. The material has been frozen and then had its water removed by sublimation under vacuum, leaving a dry porous cake or powder. Lyophilisation is used because peptides are far more stable dry than in solution.
In solution, peptides are subject to hydrolysis, oxidation, deamidation and aggregation, all of which require or are accelerated by water. Removing the water slows these processes dramatically and gives the material a workable shelf life. A peptide in solution can lose integrity in days; the same peptide dry and cold remains stable far longer.
Not necessarily. A lyophilised cake of a few milligrams can be nearly invisible, and transit can break a cake into powder or displace it up the side of the vial. Appearance is a weak indicator of integrity. The analytical report for the batch is the meaningful record.