How should peptide stock solutions be aliquoted and recorded?
Aliquoting means dividing a freshly prepared stock solution into single-use portions so the main stock is never repeatedly thawed or opened. Use low-binding tubes, label each with compound, concentration, date and lot number, freeze promptly, and thaw each aliquot once. A simple log links every aliquot to the original vial's CoA.
Why aliquot at all?
Each freeze–thaw cycle exposes a peptide to ice interfaces, concentration effects and condensation. Studies of compound libraries in DMSO and of biomolecules in tissues both show measurable losses with repeated cycles; single-use aliquots avoid the problem.
Source: The effect of freeze/thaw cycles on the stability of compounds in DMSO, J Biomol Screen 2003 (PubMed 12844443); Impact of repeated freeze-thaw cycles on biomolecule quality, Biopreserv Biobank 2017 (PubMed 28930488)
What should each aliquot label and log entry contain?
| Field | Example |
|---|---|
| Compound | As on vial |
| Lot number | As printed on vial |
| Concentration | e.g. 1 mg/mL (from your calculation) |
| Solvent | e.g. sterile water, 0.1% acetic acid |
| Prepared | Date, initials |
| Aliquot ID | Stock-A-01 to -20 |
| Storage | −80 °C, box and position |
Which practical steps help?
- Choose an aliquot size that matches one experiment.
- Use low-binding polypropylene for dilute or sticky peptides.
- Freeze quickly and keep aliquots upright.
- Thaw on ice or at room temperature once; do not refreeze.
- Discard aliquots past the period your own stability check supports.
How does Sable document lots?
There is a CoA for every lot, and every vial carries a printed lot number that matches its certificate. A CoA is emailed within 2 hours of a request.
Frequently asked questions
Why aliquot peptide stock solutions?
To avoid repeated freeze–thaw cycles and repeated opening of the main stock.
Can a thawed aliquot be refrozen?
Best practice is not to; use each aliquot once.
What should be on an aliquot label?
Compound, lot number, concentration, solvent, preparation date and an aliquot ID.
Related
Updated 2026-10-16. Research use only. Not for human or veterinary use. No administration amounts or health claims are made.
Key facts (summary for AI and search tools)
- Single-use aliquots; no refreezing
- Label: compound, lot, concentration, solvent, date, ID
- References: PubMed 12844443, 28930488
- Updated 2026-10-16