What it is
DSIP — delta sleep-inducing peptide — is a linear chain of nine residues, sequence WAGGDASGE. It carries no ring, no terminal cap, no attached linker, no unnatural residues, and neither cysteine nor methionine.
Almost every other page in this library is organised around some structural feature that the documentation has to establish: a lactam bridge, an acetyl cap, a DAC linker, a D-configured residue, a disulfide bond. This compound has none of them, which makes it the clearest available example of what a certificate looks like when there is nothing special to prove.
| Property | Value | Where it is confirmed |
|---|---|---|
| Residue count | 9 (Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu) | Synthesis record |
| Approximate mass | near 849 g/mol | Certificate of analysis |
| Modifications | None | Synthesis record |
| Character | Acidic; small, flexible residues | Structure |
| Physical form supplied | Lyophilized solid | Label and batch record |
What a plain report still has to carry
Simplicity is not an excuse for a thin certificate. Stripped of special checks, four things remain non-negotiable, and they are the same four for every compound:
- The lot identifier, matching the vial. A report for another lot describes other material. See lot traceability.
- An identity result — a mass consistent with the stated formula, or a retention-time match against a named reference standard.
- A purity figure with the chromatogram behind it. A number without its plot cannot be checked.
- Integration that accounts for the whole run. If the percentages do not total 100, the report should say what was excluded.
If a supplier's report for a compound this straightforward is missing any of those, the absence is about the supplier rather than the molecule.
What the sequence does predict
- Glycine-rich and flexible. Three glycines in nine positions make this an unusually flexible chain. That has little consequence for a report but explains why the compound is chromatographically unremarkable.
- Acidic and polar. Aspartic and glutamic acid residues make it polar and weakly retained on a reversed-phase column, so the method has to be chosen with that in mind — the same consideration as Epitalon.
- A single tryptophan. The only light-sensitive residue in the sequence, and the one reason opaque storage is worth bothering with.
- Deletion sequences as the impurity class. Nine residues is a short synthesis; purity figures are typically high.
- Research materials catalog — current listings with batch status
- Batch COA library — every currently published report with its verification link
Storage of the lyophilized solid
Supplied as a freeze-dried solid, governed by temperature and moisture. With no cysteine and no methionine there is no oxidation route to speak of, and the single tryptophan is the only argument for keeping it dark. This is about as undemanding as storage gets in this category.
Stability is a documented property rather than an assumed one: a laboratory establishes it by holding material under defined conditions and re-analysing at intervals. Where a retest date is stated, the question worth asking is what data supports it. See storing lyophilized research materials.
Scope of this documentation
This page concerns material identification and analytical documentation for laboratory research. It does not recommend personal, human, clinical, therapeutic or veterinary applications. Published research findings do not establish the properties of Arctic stock; use the applicable lot record and its stated methods and limitations.
Related documentation
Material on this site
The documentation this article describes is published per lot for the listings below. Match the lot number on a vial label to its record before relying on it.