Temperature excursion: difference between revisions
Diff·revision 17 → 18·16:48, 6 Oct 2025
Difference between revision 17 and revision 18 of Temperature excursion. 2 lines changed; the page grew by 341 bytes.
| Revision 17 — 00:34, 19 Sep 2025 RepackRadek (talk) add the shelf temperature and the primary drying step to the cycle description 17,311 bytes +1,332 | Revision 18 — 16:48, 6 Oct 2025 FmocFrancis (talk) add the stopper material, since it affects moisture ingress 17,652 bytes +341 | ||
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| 112 | The practical consequences are that a freezing excursion may cause more damage than a warming excursion of far greater apparent severity; that the damage is often physical rather than chemical, so a purity assay that resolves degradation products may not detect it while a size-exclusion or subvisible-particle method does; and that repeated freeze-thaw cycles are more damaging than a single freezing event of the same total duration, because each cycle regenerates the interface.{{r|bhatnagar2007,manning2010}} | 112 | The practical consequences are that a freezing excursion may cause more damage than a warming excursion of far greater apparent severity; that the damage is often physical rather than chemical, so a purity assay that resolves degradation products may not detect it while a size-exclusion or subvisible-particle method does; and that repeated freeze-thaw cycles are more damaging than a single freezing event of the same total duration, because each cycle regenerates the interface.{{r|bhatnagar2007,manning2010}} |
| 113 | 113 | ||
| + | 114 | For lyophilised material the picture reverses. A dry cake has no ice to form and no interface to create, and freezing a sealed lyophilised vial is generally regarded as harmless — which is why frozen storage is the recommended long-term condition for dry peptide while being contraindicated for the same peptide in solution.{{r|ich_q1a}} | |
| + | 115 | ||
| 114 | == References == | 116 | == References == |
| 115 | {{reflist}} | 117 | {{reflist}} |