DSIP Raw Material Supplier

Naming

DSIP: the name, the sequence and the registry number

DSIP is the four-letter abbreviation under which a nonapeptide with the sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, or WAGGDASGE in one-letter code, is traded. Its registry number is CAS 62568-57-4, its PubChem entry is CID 68816, its formula is C35H48N10O15 and its molecular weight is 848.8 g/mol. The expanded form of the abbreviation, delta sleep-inducing peptide, is the historical name under which the sequence was registered. It is reproduced here because it is the name in the registry, not because this page makes any claim about it, and the sequence and the CAS number are the identifiers to use on a purchase order.

Nine residues is long enough for the sequence itself to be the thing that matters. A substitution, a missing glycine or an amidated instead of a free-acid terminus each gives a different substance, and DSIP as registered ends in glutamate with a free carboxyl group, which is what the formula C35H48N10O15 describes. Analogues with a modified residue circulate under names that resemble DSIP; they are different compounds and would need their own registry numbers on a quotation. A molecular-weight result near 848.8 g/mol, read together with the CAS number, is how a buyer confirms that what is being offered is the parent nonapeptide and not a relative of it.

The CAS number pins the sequence; it leaves open two things that affect a weighed quantity. One is the salt form, which adds counter-ion mass to the gross weight. The other is water, which a lyophilized cake always holds to some degree. Both are stated on a quotation if you ask, and neither is reported on the public summary. The rest of this page covers documentation, formats, ordering and handling for a procurement reader, and stops there; what DSIP does is not a subject this site writes about. DSIP is supplied for research use only.

Batch record

Two public DSIP lots and what they report

The Pepti library currently holds two public DSIP records, one for a 2 mg fill and one for a 5 mg fill. Both report an HPLC purity result of 99.8%, so the published range for this compound is a single figure rather than a spread. That is a coincidence of two lots, not a promise; the next lot will be tested in the same way and will report whatever it reports. Each record also carries a molecular-weight result from mass spectrometry, the manufacturing date, the test date and a retest date set about two years after manufacture.

The certificate answers two questions: is the main peak DSIP, and how much of the chromatogram is that peak. It does not answer how much material is in the vial as a measured fill, how much of the weighed mass is water or counter-ion, whether endotoxin or bioburden was tested, or what the peptide content is on a net basis. Those are legitimate questions for a buyer to have. They are answered by tests the buyer commissions, and the lot number printed on the certificate and on every vial label is what connects an outside result back to this material.

Ask for the record before paying. For allocated stock the quotation carries the lot reference and the matching row in the batch table on this page can be read straight away. For a lot still in production the certificate is issued on the same template once testing is complete and is sent with the order documents. The quality page explains the template; the guide on comparing supplier quotations explains what to look for when two suppliers both quote a purity figure.

Handling

Keeping DSIP as it was documented

DSIP is dispatched dry: freeze-dried cakes in stoppered, capped vials, or weighed powder in a sealed container inside cold-chain packing. The certificate gives a retest date, and that date is a calendar prompt for the holder to re-examine the lot, not a point at which the material changes. Log it on receipt alongside the lot number and the date the parcel arrived.

Between receipt and the retest date the rules are the same as for any lyophilized peptide held as reference material: closed container, cold, dark, opened only when needed and never left to warm and cool repeatedly. A cake that has been warmed, opened and chilled again several times will eventually show it on a chromatogram, and by then the supplier is a long way from the cause. None of this is guidance on use. The storage and retest guide covers the reasoning and what to do when a held lot reaches its retest date.

DSIP supply questions