See the analytical data behind every lot

How PrimeGen certificates of analysis work

Every released lot is documented twice. An in-house reverse-phase HPLC assay establishes chromatographic purity, and an independent third party laboratory then repeats HPLC and adds mass spectrometry to confirm identity. The certificate published for a lot is the document produced for that specific synthesis; it is never a representative certificate carried across from an earlier batch, and it is never an internally generated summary of somebody else's testing.

Certificates are distributed digitally rather than enclosed in the shipment. That keeps the document tied to a lot record that can be reissued, corrected or supplemented with raw data, instead of a printed sheet that can be separated from the vial it belongs to. Chromatograms and mass spectra behind any certificate can be requested for a specific lot.

Because vials are labelled with placeholder lot and expiry fields in product photography, the authoritative lot detail always comes from the certificate record rather than from a marketing image. If a document and a physical vial ever disagree, contact laboratory support before using the material.

• Release specification is at least 98% purity by RP-HPLC.
• Identity is confirmed by mass spectrometry against the expected molecular weight.
• Third party testing is performed by an independent analytical laboratory, not in house.
• Raw chromatograms and spectra are available on request for any released lot.

Reading an analytical report

A chromatogram shows detector response over retention time. The target peptide elutes as a dominant peak, and purity is reported as that peak's integrated area divided by total integrated peak area, usually at 214 nm where the peptide bond absorbs. Small satellite peaks are normal in solid-phase synthesis: deletion sequences, oxidation products and truncations sit close to the target and are exactly what the assay is designed to quantify.

The mass spectrum answers the question chromatography cannot. Two molecules of similar hydrophobicity can co-elute, so identity is confirmed by measuring the molecular ion and comparing it against the theoretical mass for the sequence. A report that matches on both axes — a dominant peak with correct mass — is the pair of evidence worth requiring from any supplier.

How a lot moves from synthesis to a published certificate

Material begins as a solid-phase synthesis, assembled residue by residue on a resin support before cleavage, deprotection and precipitation. The crude product at that stage always contains related substances — truncated chains where a coupling was incomplete, deletion sequences, oxidised or partially deprotected species — and the purification step exists to separate them. Preparative reverse-phase chromatography collects the fractions containing the target sequence, which are pooled, concentrated and freeze dried into the amorphous cake that ends up in the vial.

In-house RP-HPLC is run first as a gate. If the chromatogram shows an unresolved shoulder, a rising baseline or a secondary peak above the release limit, the material does not progress and the lot is not offered. Only material that passes internally is submitted onward to an independent laboratory, which repeats the chromatography on its own methods and adds mass spectrometry to confirm identity against the theoretical mass of the sequence.

The certificate published here is that external report, tied to the lot code printed on the vial label. Filling and sealing happen under inert gas into USP Type I borosilicate vials, the cake is visually inspected, and the lot is only then released into inventory. Because each cycle is documented separately, a repeat order months later carries its own certificate rather than inheriting an earlier one.

What an independent analytical report can and cannot tell you

A certificate of analysis is a snapshot of a defined quantity of material at the moment it was tested. It is strong evidence about that lot and silent about everything else. Reverse-phase HPLC quantifies how much of the integrated peak area belongs to the principal peak, which is why a purity figure is always a chromatographic purity and always method dependent — column chemistry, gradient and detection wavelength all shape the number. Mass spectrometry answers a different question entirely, confirming that the observed molecular ion matches the theoretical mass of the intended sequence.

Neither method addresses sterility, endotoxin load or pyrogenicity, and none of the reports published here claim to. Research peptides are supplied as non-sterile laboratory chemicals; any assay requiring sterile or endotoxin-controlled input needs its own downstream processing and its own verification. Similarly, a certificate says nothing about how the vial has been stored since release. Documentation and handling are complementary, not interchangeable.

Reading the report in order makes it faster to interpret. Confirm the compound name and the lot code match the vial in front of you, then the test date, then the chromatogram: look for a dominant single peak with a stable baseline rather than a cluster of partially resolved shoulders. Move to the mass spectrum and check the observed mass against the theoretical mass quoted in the header. Finally read the numeric summary — purity, net peptide content where reported, and water or counter-ion content — because that is what converts a vial into a defensible concentration in your protocol.

Using certificates to compare lots over time

A single certificate proves one thing: that one lot met specification on the day it was released. The more useful exercise, and the one that separates a real quality programme from a marketing document, is comparing certificates for the same compound across successive releases. Chromatographic purity should sit in a narrow band rather than drifting; the impurity profile should look structurally similar from lot to lot; and the observed mass should land on the same calculated value every time. Variation in any of those is a question worth asking before it becomes a question about your data.

That comparison is also how a laboratory decides whether a repeat order is genuinely the same reagent. A study that ran for three months on one lot and then continues on another has changed a variable, and the certificate pair is the evidence for how large that change is. Where a series can be purchased in one order, keeping every vial on a single lot code removes the question entirely — which is why long dose-ranging work is usually bought as a block rather than replenished.

Every certificate on this page names the compound, the fill weight, the lot code, the analytical methods and the independent laboratory that performed the confirmation. Raw chromatograms and mass spectra behind any published summary can be requested through laboratory support, and are supplied as the original instrument output rather than as a redrawn figure.