I have a bunch in the freezer. I think I'm leaning towards putting any new stuff in the fridge.
Peptides should be stored in solution only for short periods of time. For long-term storage the peptide should be lyophilized from a volatile buffer or solvent and stored desiccated at -20 °C.
Table 7:The best storage and handling conditions will depend on peptide sequence. However, despite the individuality of peptide sequences, some general recommendations for peptide handling can be made (Table 7).
Duration of storage
Concentrated stock solution (0.5–2 nmol/μL): storage duration depends on peptide
Short-term (≤3 months): high concentration (1–100 pmol/μL) liquid solution at 4 °C or frozen solution at −20 °C to −80 °C
Medium-term (3 months to 1 year; peptide-dependent): frozen solution at high concentration
Long-term (>1 year): lyophilized at −20 °C to −80 °C
Grant, Gregory A. (2002). Synthetic Peptides: A Users's Guide. p 283.
Table 7:
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Recommendations for the Generation, Quantification, Storage, and Handling of Peptides Used for Mass Spectrometry–Based Assays
AbstractBACKGROUND. For many years, basic and clinical researchers have taken advantage of the analytical sensitivity and specificity afforded by mass specacademic.oup.com
Tl;dr: so you're on the pro-freezer side of the debate?
I'm fridge but really fridge/freezer seems minutiae compared to either vs. room temperature.
There is nothing to debate. The science on this has been known for decades. In general if you want to store lyophilized peptides for > 3 months, the freezer is the best place.
Like the above study says, it depends on the peptide. If you go read the study that ghoul grabbed graphs from but didn't link the source, it shows that the bilirubin actually degraded quite a bit in the refrigerator (4%) but not in the freezer.
All is probably fine, just room temp out of the sun at a minimum.
YupFridge is a good compromise, based on best guesses.
Bilirubin is not a good example. Not a peptide.
Was it reconstituted? If so, kinda interesting (light exposure conditions?), but doesn't provide insight into the questions being asked here.
Bilirubin is not a good example. Not a peptide.
BTW, I was lazy in referencing the example. It was bivalirudin that degraded 4% at 4C. Bivalirudin Is a peptide.
My guess is it’ll be different for each individual peptide.
Phizer says explicitly not to freeze Lyophilized HGH powder and to store it under refrigeration.
For sure. The study I referenced earlier explicitly says it depends on the peptide, but then says the general advice is to store at -20C.
HGH is s tough one. Definitely, as you've pointed out, some say refrigerate rather than freeze. There a bunch of other manufacturers, though, who say store their's at -20C. Fortunately, I'm in a test of UGL HGH that has been stored for 6 months in the freezer. We already have a before test of the batch so the after test should give us some insight on whether this UGL HGH is best stored in the freezer.