Every claim on this site reduces to one document: the certificate of analysis. This page explains what we test, how we test it, and how to get the certificate for the exact batch in your hand — because a purity figure you can't verify is just marketing.
HPLC — how much of the vial is the compound
High-performance liquid chromatography pushes a dissolved sample through a separation column under pressure. Each compound in the sample exits the column at a different time, drawing a peak on the chromatogram — one compound, one peak. Purity is the main peak's share of the total peak area, so a figure of 98.7% means 1.3% of the material is something else: typically deletion sequences, near-identical peptides missing one residue from an incomplete coupling step during synthesis.
That is why we publish the chromatogram itself in every certificate, not just the number. You can see the minor peaks and check the calculation.
Mass spectrometry — whether it's the right compound
A clean chromatogram tells you the vial contains one dominant compound. It doesn't prove it's the compound on the label. Mass spectrometry measures the molecular weight of the material and confirms it matches the target sequence — the identity check that makes the purity figure meaningful. Every certificate carries both.
Requesting the certificate for your batch
Every vial we ship carries a printed batch code.
- Find the code on your vial label (or your order confirmation).
- Send it to us through the contact page, with your order number if you have it.
- We reply with the full certificate — chromatogram, purity calculation, mass confirmation, test date — usually the same working day.
- Check the batch code on the document against the one on your vial. If they don't match, tell us immediately.
Certificates are also available before purchase for any batch currently in stock. Serious buyers ask first; we'd rather you did.
Handling, storage and transit
Lyophilised peptides are shipped sealed and are stable at ambient temperature for the short transit windows our UK-only dispatch allows — typically 2–4 working days, tracked. For long-term storage, keep sealed vials at −20°C. Reconstituted material belongs at 2–8°C and has a working life measured in weeks, which varies by compound; the specification table on each product page carries the specifics.
All testing is performed for quality-control purposes on research material. Products are supplied strictly for laboratory research and are not for human or animal consumption. 18+.