DSIP (delta sleep-inducing peptide) is a nine-residue peptide first isolated in 1977. Because it is short and has no unusual residues, a DSIP certificate of analysis is easy to check if you know the numbers it should hit. This page lists them.
DSIP identity at a glance
- Sequence: Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE)
- Molecular formula: C35H48N10O15
- Average molecular weight: 848.8 g/mol
- Monoisotopic mass: 848.33 Da
- CAS number: 62568-57-4
- Form: lyophilized powder
What the mass spectrometry result should show
The identity section of a DSIP COA should report an observed mass that matches DSIP. In electrospray MS you will usually see one or both of these ions:
- [M+H]+ at about 849.3
- [M+2H]2+ at about 425.2
Some labs report the deconvoluted mass instead, which should read about 848.3 (monoisotopic) or 848.8 (average). A result far from these values means the sample is not DSIP, whatever its purity.
What the purity result should show
HPLC purity for research-grade DSIP should be 98% or higher, shown with the chromatogram. Look for one dominant peak. DSIP contains one tryptophan, so impurities from oxidation can appear as small nearby peaks. They should be minor and clearly separated.
Net content: 5 mg vs 10 mg vials
Purity does not tell you how much DSIP is in the vial. Net peptide content does. For a 10 mg vial, expect a net result at or above 10 mg. A report for a 5 mg lot does not cover a 10 mg vial: each size is a separate lot and needs its own report.
Storage of the lyophilized powder
Store sealed vials at −20°C, dry and protected from light. The tryptophan residue is the part most sensitive to light and oxidation.
DSIP COA checklist
- Lot number on the report matches the vial.
- Test date and a lab you can verify.
- Mass result near 849.3 ([M+H]+) or 425.2 ([M+2H]2+).
- HPLC purity of 98% or more, with the chromatogram.
- Net content at or above the label amount, for the right vial size.
Every Nyxo DSIP lot carries an ML lot number, and its report goes up on our certificates page when that lot ships. See DSIP.
For laboratory research use only. Not for human or animal use.