PE-22-28 Testing | Identity & Purity Check

What PE-22-28 is

PE-22-28 is a seven-residue peptide corresponding to residues 22–28 of spadin, itself a fragment of the sortilin propeptide. It is a small, water-soluble sequence that is straightforward to synthesise — which cuts both ways. Small peptides are cheap to make well and cheap to make badly, and a short sequence gives an identity check less to work with: fewer residues mean fewer chromatographic and spectral features to distinguish it from a neighbour. PE-22-28 is a newer entrant on the research market, sold with no regulated manufacturing behind it and often in sub-milligram to low-milligram quantities where fill accuracy matters most.

Why get your PE-22-28 independently tested

Fill accuracy on a tiny label claim: PE-22-28 is often sold in small milligram amounts, where a few hundred micrograms of error is a large percentage of the claim. The net-peptide assay reports measured milligrams against the label.
Counter-ion and water share: on a short, salt-heavy peptide, trifluoroacetate and moisture can be a large fraction of gross mass. Only a content assay against a reference standard separates peptide from packaging.
Synthesis byproducts: even a heptapeptide picks up deletion and incomplete-deprotection species. Chromatographic purity as area percent reports how much of the material is the intended sequence.
Identity on a compound with little market history: a newer peptide has fewer independent results to compare against, which makes a documented retention-time and UV-spectral match against a reference standard more valuable, not less.

What we measure on PE-22-28

Every PE-22-28 certificate reports identity (retention-time and UV-spectral match against a certified PE-22-28 reference standard), chromatographic purity as area percent, and net-peptide content in milligrams per vial, by reversed-phase HPLC with diode-array detection at 214 nm.

Every result is issued as a certificate of analysis you — or anyone you forward it to — can verify cryptographically. Reporting identity, purity, and milligram content is the point: a vial can be pure and still underfilled, so we report all three. More on purity vs. net-peptide content and how to read a peptide COA.

Our scope — stated plainly

Testing is RP-HPLC-UV against a certified reference standard; because PE-22-28 is a less common compound, a standard may need to be sourced before analysis, which can affect turnaround. KMD Analytical is an independent laboratory. We do not perform mass spectrometry, sterility, endotoxin, heavy-metal, or residual-solvent testing.

KMD is an independent RP-HPLC-UV lab. We do not run LC-MS / mass-spec, sterility, endotoxin, or heavy-metal testing. If your job needs a capability we don't have, we'll say so.

PE-22-28 testing — FAQ

Is a seven-residue peptide harder to identify by HPLC?

It gives the method less to work with than a 30-residue sequence, but retention time and UV spectrum against the reference standard still discriminate it from other short peptides under our conditions. What HPLC-UV cannot do is sequence an unknown; identity is always a match or a mismatch against a named standard, and the certificate says which.

My vial is labelled in micrograms — can you still quantify it?

Yes, within the working range of the method. Tell us the label claim on the order form so the dilution is planned for it. Very small fills are exactly where a content assay earns its keep.

Do you test PE-22-28 in solution?

Lyophilised vials are the norm and preferred. If your material is already in solution, say so when ordering — we dilute from an aliquot and report content per vial as received.

Test your PE-22-28 →Verify a certificate Pricing & turnaround

PE-22-28 (Spadin Analog) Testing & Verification