Lyophilised research peptides are stored cold, dry and dark: refrigerated at 2 to 8 \u00b0C for the weeks they will be in use, or frozen at minus 20 \u00b0C for longer holding, with the vial sealed and out of light. Once a vial has been reconstituted with bacteriostatic water it is kept refrigerated at 2 to 8 \u00b0C, never frozen and thawed repeatedly, and used within the multi-dose window the preservative allows, which the USP convention for opened multi-dose containers puts at 28 days. Those two rules cover almost every vial in a research catalogue; the rest of this page is the reasoning and the exceptions.<\/p>\n
A lyophilised (freeze-dried) peptide is a dry cake with almost no water in it, which is what makes it stable. Its enemies are heat, light and moisture, in that order. Refrigeration at 2 to 8 \u00b0C is the working standard for vials that will be used over the following weeks; a freezer at minus 20 \u00b0C is the standard for vials being held for months. Keep the vial in its box or a closed container so the powder is not exposed to light, and keep the stopper dry.<\/p>\n
Peptide manufacturers’ handling guides (Bachem, Sigma-Aldrich and GenScript all publish one) agree on the same points: store lyophilised material cold and desiccated, keep it sealed, and let a cold vial warm to room temperature before it is opened. That last step matters more than it sounds: a vial opened straight from the fridge draws condensation onto the cold powder, and water is the one thing a freeze-dried cake should not meet before it is meant to.<\/p>\n
No. Lyophilised peptides tolerate the days in transit at ambient temperature that a domestic courier involves, which is why research suppliers ship them without cold packs. Orders from Vistara Labs travel within Canada by Canada Post, typically one to three days by Xpresspost and three to five by standard post, and the vials go into the fridge on arrival. What the powder should not see is a hot car, a windowsill or a radiator; heat over days, not hours, is what degrades it.<\/p>\n
Once bacteriostatic water is added, the peptide is in solution and the clock starts. Store the solution refrigerated at 2 to 8 \u00b0C, upright, protected from light, with the stopper swabbed before every access. Do not freeze a reconstituted vial that will be accessed again: freeze-thaw cycles are the fastest way to aggregate a peptide in solution, and a vial that goes cloudy or grows strands after thawing has usually been through exactly that. If a large volume needs to be kept for a long period, laboratories split it into single-use aliquots and freeze those once, at minus 20 \u00b0C, thawing each one only when it is used.<\/p>\n
The 28-day figure comes from pharmacy practice, not from peptide chemistry: USP General Chapter 797 sets a 28-day beyond-use date for an opened multiple-dose container of a preserved product unless the label says otherwise, and bacteriostatic water’s 0.9% benzyl alcohol is the preservative that makes a multi-dose vial possible in the first place. Plain sterile water has no preservative, which is why a vial reconstituted with it is treated as single-access. The longer explanation is in bacteriostatic water explained<\/a>.<\/p>\n Stability in solution depends on the sequence. Peptides containing cysteine, methionine or tryptophan are prone to oxidation; those with asparagine or glutamine can deamidate; a glutamine at the N-terminus can cyclise. Sequences with several of these residues are best reconstituted in smaller volumes closer to use rather than held in solution for weeks. Copper peptides such as GHK-Cu are stable but light-sensitive in solution; the blue colour is the copper and should stay clear. Cloudiness, visible strands or a gel that will not disperse mean the solution should not be trusted; the causes are covered in why peptides gel or go cloudy<\/a>.<\/p>\n Unopened, bacteriostatic water is stored at room temperature away from light, like any sterile water product. Once the stopper has been punctured it follows the same 28-day multi-dose convention as anything else preserved with benzyl alcohol. It should not be frozen, and a vial that has turned cloudy or shows particles is discarded. A 10 mL vial reconstitutes five 10 mg peptide vials at 2 mL each; the per-compound volumes are on the reconstitution guide<\/a>.<\/p>\n Vistara Labs supplies peptides and bacteriostatic water as laboratory research materials. The storage conditions on this page describe how the materials are kept stable; they are not instructions for any other use.<\/p>\n<\/div>\n Yes. Minus 20 \u00b0C is the standard for holding sealed lyophilised vials for months. Let the vial reach room temperature before opening it so condensation does not form on the powder.<\/p>\n The multi-dose convention is 28 days after the stopper is first punctured, taken from the USP 797 beyond-use rule for preserved multiple-dose containers. Sequence-sensitive peptides are better reconstituted in smaller volumes closer to use.<\/p>\n Not if it will be accessed again. Repeated freezing and thawing aggregates peptides in solution. Laboratories freeze single-use aliquots once instead.<\/p>\n Yes, both before and after reconstitution. Light degrades several peptides over time; the box the vial arrived in, or a closed container in the fridge, is enough.<\/p>\n Days at ambient temperature in transit do not harm a lyophilised peptide. Refrigerate it on arrival and let it come back to room temperature before opening.<\/p>\n Products: bacteriostatic water<\/a> and the research peptide catalogue<\/a>. Certificates of analysis are published on the Lab Results<\/a> page.<\/p>\nWhich peptides are less stable in solution?<\/h2>\n
What about bacteriostatic water itself?<\/h2>\n
Frequently asked questions<\/h2>\n
Can I keep lyophilised peptides in the freezer?<\/h3>\n
How long does a reconstituted peptide last in the fridge?<\/h3>\n
Can I refreeze a reconstituted vial?<\/h3>\n
Does the vial need to be kept in the dark?<\/h3>\n
Is it a problem if the peptide arrived warm?<\/h3>\n