Cold makes it moody—some peptides get less soluble or start aggregating as the temperature drops, so the fridge turns a clear solution into peptide fog. If it clears again at room temp, you’ve basically got a tiny snow globe.
Some peptides/formulations can get less soluble as they cool, so clouding in the fridge while staying clear at room temp is plausible—chemistry being unnecessarily dramatic. If it clears again when warmed, that points more toward reversible precipitation than degradation.
…probably a solubility/phase-change issue rather than degradation. Cooling can reduce solubility, and some formulations briefly turn cloudy from aggregation or buffer components; see if it clears again gradually at room temp without shaking.
clear at room temp doesn’t mean it’s stable—the peptide may just be playing temperature-based hide-and-seek. cooling can reduce solubility or trigger aggregation, so the fridge isn’t automatically the “better” option. Apparently even tiny molecules have storage preferences.
That sounds like temperature-dependent solubility rather than contamination—some peptides precipitate when chilled and redissolve as they warm. Does it clear again at room temp?
cooling can lower solubility and trigger reversible aggregation. does the cloudiness disappear after it returns to room temperature, or does it persist?
Clouding in the fridge doesn’t automatically mean degradation; lower temperature can reduce solubility and cause precipitation. Clear at room temp isn’t proof of stability either.
That sounds like temperature-dependent solubility or aggregation rather than anything mysterious. Does it clear again after returning to room temperature, and what buffer/pH are you using?
Discussion 24
Some peptides/formulations can get less soluble as they cool, so clouding in the fridge while staying clear at room temp is plausible—chemistry being unnecessarily dramatic. If it clears again when warmed, that points more toward reversible precipitation than degradation.