Per vial, USD
| Fill weight | 100+ | 1,000+ | 2,500+ | Order |
|---|---|---|---|---|
| 10 mg | $22.50 | $18.90 | $18.45 |
Ordering at volume
The thing worth settling before two DSIP quotes are compared is what the number in the vial means. A 10 mg fill is 10 mg of solid, and for any synthetic peptide some of that solid is counter-ion and residual water. Suppliers differ over whether they state gross fill or net peptide content, and a rate that looks keen can simply be a different measurement. Ask at quote which basis the fill is stated on, have it written down, and put like against like.
Beyond that, this is an ordinary nine-residue synthesis with no ring closure, no lipid and no metal, so the chemistry itself sets no long queue. It is carried as standard catalog stock in a single fill, which means the count of DSIP vials is the only number that decides the DSIP rate; every other line on the order runs its own ladder. Contract terms open above ten thousand vials of one compound.
Ask for the certificate before a first shipment is released to stores, and check the lot printed on the vial against it. Where a quantity has to draw on more than one lot, ask at quote which lots, and request a certificate for each; every vial is printed with its own lot number. COA requests go to one address so nothing has to be chased through a sales thread.
Specification
- Compound
- DSIP
- CAS number
- 62568-57-4
- Formula
- C₃₅H₄₈N₁₀O₁₅
- Molecular weight
- 848.81 g/mol
- PubChem CID
- 68760
- Form
- Lyophilized powder, sealed vial
- Fill weights
- 10 mg
- Stock depth
- Standard catalog — Stocked in California. Each compound reaches its own tier break.
- Intended use
- Laboratory research only. Not for human or veterinary use.
What the material is
DSIP is a short synthetic peptide of nine residues, sequenced Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu. Its character comes from the two ends. A tryptophan opens the chain and is the one residue in the molecule that absorbs strongly in the ultraviolet, which is what makes the material straightforward to follow on a chromatogram. Aspartic acid in the middle and glutamic acid at the far end give it two free acidic side chains, and at 848.81 g/mol those account for much of the mass beyond the small residues between them.
The vial holds an off-white lyophilized solid behind a crimped closure. A synthetic peptide is isolated from purification with a counter-ion and a little residual water, so part of the solid in any vial is not peptide. How the fill on this line is stated, as gross solid or as net peptide, is settled on the quote rather than read from a catalog row.
Storage and reconstitution
Sealed vials keep well at −20 °C so long as they stay dry and protected from light. A short warm spell on the road does no harm while the seal holds and the solid is intact. Warm a vial through before the crimp comes off, so that room air deposits no moisture on cold solid.
The solid takes to water, or to a buffer suited to the assay, without difficulty. An acidic peptide goes into solution most readily at or a little above neutral pH, so a preparation that stays hazy usually points at a buffer sitting too low rather than at the material. Hold the solution cold and dark, and aliquot it if more than a single draw is planned; freeze-thaw cycling is the usual reason a dissolved peptide stops looking clear.
Buying questions
Does a 10 mg DSIP vial contain 10 mg of peptide?
It contains 10 mg of lyophilized solid. For any synthetic peptide, part of that solid is counter-ion and bound water, so net peptide content is somewhat lower. Ask at quote whether a fill is stated as gross solid or net peptide when comparing suppliers, because the two numbers are not the same measurement.
How should a DSIP quote be compared against another supplier's?
Line the certificates up before the rates. Compare the basis each fill is stated on rather than the fill alone, then compare what each certificate actually reports and whether the supplier will name the specific lot being shipped. The quality page sets out what ours covers.
Can a large DSIP order draw on more than one lot?
It can above a certain quantity, and the quote is where to ask which lots. Every lot carries its own certificate and every vial is printed with its own lot number, so a mixed shipment stays traceable. If one lot has to cover the whole quantity, say so at quote and it is priced that way.
Why does a DSIP solution need a buffer near neutral pH?
Because the two acidic side chains are what carry it into solution, and they are least charged at low pH. In practice a buffer at or slightly above neutral dissolves the solid cleanly while an acidic one can leave a haze that is easy to mistake for poor material.
