Most degradation in a research setting does not happen in transit. It happens on a bench, in a fridge door, or in a vial that was frozen and thawed one time too many. Handling protocol is the cheapest variable to control and the one most often left undocumented.
In transit
Lyophilised peptide powder is far more stable than the reconstituted solution. Short ambient shipping windows — two to three days — are well tolerated by the large majority of research peptides, which is why standard expedited shipping is normal practice rather than a corner being cut. Cold packs matter most for pre-reconstituted material and for a small set of unusually labile sequences.
On arrival
- Inspect the vial: the cake should be white to off-white, intact or lightly collapsed. A yellowed or oily residue is a reason to stop.
- Let the vial reach room temperature before opening. Cold glass pulls in atmospheric moisture the moment the seal breaks.
- Log the lot number against the COA before the vial goes into storage, not after.
- Store lyophilised material at -20°C, protected from light, in the back of the freezer rather than the door.
Reconstitution
Add diluent slowly down the inner wall of the vial rather than directly onto the cake. Let it dissolve on its own or swirl gently; do not shake. Vigorous agitation introduces shear and foaming, both of which denature peptides. If particulate remains after several minutes at room temperature, note it — it is data, not a nuisance.
Our reconstitution calculator will convert vial strength, diluent volume, and target dose into a per-unit measurement so the arithmetic is not done by hand at the bench.
After reconstitution
- Refrigerate at 2–8°C and protect from light.
- Aliquot before freezing if the solution will be used across many sessions — one thaw per aliquot.
- Label every aliquot with compound, concentration, date, and lot. Unlabelled aliquots become unusable data.
- Treat freeze-thaw cycles as a logged variable, not an afterthought.
If your protocol does not record how many times a vial has been thawed, your purity data has an expiry date you cannot see.