What is DSIP?
DSIP, an abbreviation of Delta Sleep-Inducing Peptide, is a small endogenous peptide belonging to the class of linear, unmodified oligopeptides. It is composed of nine amino acid residues arranged in the sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (single-letter code WAGGDASGE), presenting free amino (N-) and carboxyl (C-) termini rather than acetylated or amidated end groups. The compound carries CAS registry number 62568-57-4, corresponds to the molecular formula C35H48N10O15, and has a molecular weight of 848.81.
Structurally, DSIP is notable for its glycine-rich, largely uncharged backbone punctuated by two acidic residues, aspartate (Asp) at position 5 and glutamate (Glu) at position 9, which contribute negative charge and influence its solubility profile in aqueous media. A single tryptophan (Trp) residue at the N-terminus provides a UV-active chromophore useful for spectroscopic detection, while the serine (Ser) residue introduces a hydroxyl-bearing side chain. The absence of cysteine means the peptide contains no disulfide bridges and exists as a single linear chain.
The peptide was first described following its isolation from the cerebral venous blood of sleeping rabbits, and it is studied within neurochemistry and endogenous-peptide research as a naturally derived reference sequence. In the research setting DSIP is used as a characterized peptide standard and as a subject of in-vitro and preclinical investigation into small-peptide chemistry and signaling models. This material is offered strictly for laboratory research use only and is not a drug, supplement, or article intended for human or veterinary use; no therapeutic properties are described or implied.
Reconstitution & handling
DSIP is supplied as a lyophilized (freeze-dried) powder and is typically reconstituted for laboratory work by adding a compatible sterile solvent to dissolve the solid into a defined stock solution. Because the sequence contains two acidic residues and a hydrophilic, glycine-rich backbone, it is generally soluble in aqueous buffers and in bacteriostatic or sterile water; if initial wetting is slow, a small volume of dilute acetic acid or an appropriate buffer near neutral pH can assist dissolution before further dilution. Solvent should be directed gently down the wall of the vial rather than forced directly onto the powder, and the vial swirled rather than vigorously shaken, since aggressive agitation can promote foaming and mechanical stress on the peptide.
Reconstitution should be performed with clean technique using pre-chilled solvent, allowing the material to dissolve fully at low temperature before use. Peptides in solution are less stable than the dry solid, so stock solutions are best prepared in the volume needed for near-term work and any remaining material aliquoted to limit repeated handling. This information concerns dissolution chemistry and handling only and is not administration guidance.
Storage & stability
In its lyophilized form, DSIP is best stored sealed and protected from moisture and light at low temperature, typically frozen at or below -20 degrees Celsius for long-term stability, where the dry powder remains stable for extended periods. Once reconstituted, the peptide is markedly less stable and should be kept refrigerated for short-term use or frozen in single-use aliquots for longer storage; dividing the stock into aliquots minimizes repeated freeze-thaw cycles, which can degrade peptide integrity over time. Allowing vials to reach room temperature before opening reduces condensation and moisture uptake that can accelerate hydrolysis of the material.
How it's tested
The identity and purity of DSIP are verified analytically before release. Purity is assessed by reversed-phase high-performance liquid chromatography (HPLC), with this lot characterized at ≥99% purity, resolving the target peptide from process-related impurities and truncated sequences. Identity and molecular weight are confirmed by mass spectrometry (MS), which matches the observed mass against the expected molecular weight of 848.81 for the C35H48N10O15 nonapeptide, and the tryptophan chromophore supports UV-based detection during chromatographic analysis. A Certificate of Analysis (COA) documenting these results is available for the material, providing traceable verification of composition and purity for research documentation.