Storing DSIP: Best Practices

❄️ Lyophilized Powder Storage

Store DSIP (Delta Sleep-Inducing Peptide) lyophilized powder at -20°C for up to approximately 1 year, or at -80°C for up to 2 years. Keep tightly sealed and protected from moisture — DSIP is hygroscopic and will absorb atmospheric water if exposed. Store under desiccation conditions, preferably with a molecular sieve or desiccant pack in the storage container.

🧪 Reconstituted Solution Storage

After reconstitution, store at -20°C for up to 1 month or at -80°C for up to 6 months. Do not store reconstituted DSIP at 4°C for extended periods due to susceptibility to proteolytic degradation. Prepare small aliquots immediately after reconstitution to avoid repeated freeze-thaw cycles, each of which accelerates peptide degradation.

⚗️ Reconstitution Protocol

Reconstitute DSIP in bacteriostatic water or sterile physiological saline (0.9% NaCl). Typical working concentrations in research protocols range from 0.1–1 mg/mL. DSIP is soluble in aqueous buffers. For stock solutions, prepare in smaller volumes (50–100 µL aliquots) and store at -80°C. Avoid glass containers if possible, as DSIP may adsorb to glass surfaces at low concentrations.

⚠️ Degradation Sensitivity

DSIP (Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu) has an extremely short in vitro half-life of approximately 15 minutes due to rapid N-terminal tryptophan cleavage by aminopeptidases. This fragility is a key pharmacological characteristic that has complicated its study and contributed to variable research results. Plasma stability studies demonstrate rapid degradation into smaller fragments (Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu and further). Handling on ice and minimal exposure to protease-containing environments is critical.

🧬 Physical Characteristics

DSIP is typically supplied as a white lyophilized powder. Molecular weight: 848.83 Da. Standard purity: ≥95–98% by HPLC. Identity confirmed by mass spectrometry. May be supplied as the free acid, acetate salt, or TFA salt — salt form affects net peptide content per stated weight.