Accepted answer
minus 80 °C is colder than anything a lyophilised cake needs. minus 80 °C is 85 kelvin below a refrigerator, and below the glass transition of a lyophilised cake the ten-degree rule of thumb stops applying at all — solid-state chemistry is not slow liquid chemistry, it is a different regime, and the failure modes that survive it are mechanical rather than chemical. A dry cake has no solvent to react in, so the marginal benefit below a domestic freezer is small and the marginal risk is not: freeze-thaw on the way in and out, and condensation on a cold stopper when you open it, are the failure modes that actually happen at minus 80 °C. Nothing here is medical advice, and research-use-only material is not approved for human use.
Start with the physical state, because lyophilised and reconstituted material have completely different storage answers.
Let a refrigerated or frozen vial equilibrate to room temperature before opening, so humid air does not condense water onto a cold cake.
Reported and extrapolated stability by condition
| State | Condition | Usable window | Basis |
|---|
| Lyophilised solid | −20 °C, sealed, dry | 24–36 months | Supplier guidance |
| Lyophilised solid | 2–8 °C, sealed | 12–24 months | Supplier guidance |
| Lyophilised solid | 25 °C, sealed | 4–8 weeks | Extrapolated (Arrhenius) |
| Lyophilised solid | 40 °C, sealed | 1–2 weeks | Extrapolated |
| Solution, preserved | 2–8 °C | 28 days | USP microbiological convention |
| Solution, preserved | 25 °C | 3–7 days | Extrapolated |
| Solution, unpreserved | 2–8 °C | 24 hours | USP microbiological convention |
Windows for the solid state are chemical; windows for solution are microbiological and usually shorter than the chemical limit.
Store with the desiccant sachet if one was supplied, inside the secondary container rather than loose in a drawer. Residual moisture is the dominant variable in solid-state stability.
Residual moisture is the dominant determinant of solid-state stability, which is why desiccants accompany lyophilised material.
Nothing here is medical advice, and research-use compounds are not approved for human use.
Keep the desiccant with the vial and the certificate with the lot code.
3I would add a sentence about light, since tryptophan-containing sequences care. – tare_and_weigh 3 months ago add a comment