What happens as a solution freezes
A review of protein stability during freezing names three main stresses:
Frozen is not the same as safe
A 2020 review of freezing biologicals stresses that stability in the frozen state should not be taken for granted. It links frozen-state degradation mainly to aggregation, and also discusses air bubbles at the ice front and mechanical stress as water expands into ice.
The same review notes that results can depend on sample size and on how fast the sample cools. That makes freezing a small vial in a lab freezer very different from a controlled freezing process.
Why repeating it is worse
Each freeze and thaw puts the solution through these stresses again. If any molecules are damaged or clumped each time, the losses add up. Peptide aggregation is also known to be affected by surfaces, concentration and agitation, all of which change during freezing and thawing.
What the labelling says
ICH guidance asks for specific storage advice to be stated, particularly for products that cannot tolerate freezing. Whether any given solution can be frozen is a question for the manufacturer's or the lab's data. Research peptides are for laboratory research only and are not approved medicines.
Educational information only. Nothing here is medical advice, dosing guidance or a recommendation to use any substance. Research peptides are not approved medicines and are not for human or animal consumption. Speak to a qualified professional and follow the law where you are.
