When is DMSO used to dissolve peptides, and what are the risks?
DMSO (dimethyl sulfoxide) dissolves many hydrophobic peptides that resist water, and is the standard solvent for compound screening libraries. It freezes at 18.5 °C, absorbs water from air readily, and can oxidise cysteine and methionine residues. Keep DMSO stocks sealed, dry and in single-use aliquots, and record water exposure.
What properties of DMSO matter?
| Property | Value or effect |
|---|---|
| Freezing point | 18.5 °C (solid in a cool lab) |
| Hygroscopicity | Absorbs water from air quickly |
| Oxidising potential | Can oxidise Cys and Met |
| Assay tolerance | Many assays limit final DMSO to low % |
| UV cutoff | ~268 nm; interferes with low-UV detection |
How does storage affect DMSO stocks?
Studies of large compound libraries found that water uptake and freeze–thaw cycles in DMSO caused measurable compound loss over time, and that water content, more than oxygen, drove much of the instability.
Source: Studies on repository compound stability in DMSO under various conditions, J Biomol Screen 2003 (PubMed 12857383); The effect of freeze/thaw cycles on the stability of compounds in DMSO, J Biomol Screen 2003 (PubMed 12844443); The effect of initial purity on the stability of solutions in storage, J Biomol Screen 2014 (PubMed 23782740)
Why avoid DMSO for Cys- and Met-containing peptides?
DMSO is a mild oxidant and has been used deliberately to form disulfide bonds; for peptides with free cysteine or methionine, alternatives such as DMF or dilute acid may be preferred if the assay allows.
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 is DMSO used for peptides?
It dissolves hydrophobic peptides that are poorly soluble in water.
What is the freezing point of DMSO?
18.5 °C, so it can solidify in a cool laboratory.
Can DMSO damage peptides?
It can oxidise cysteine and methionine, and absorbed water can reduce stock stability.
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)
- DMSO freezing point: 18.5 °C
- Hygroscopic; keep sealed
- Oxidation risk: Cys, Met
- References: PubMed 12857383, 12844443, 23782740
- Updated 2026-10-16