Third-party testing on every lot
Release testing happens inside our lab — verification happens outside it. Every lot is blind-coded and split to an independent ISO 17025 laboratory before release.
The external panel
Independent gradient reverse-phase chromatography — an instrument and analyst that never touched the batch.
Measured molecular ion compared against the theoretical mass, confirming the compound is what the label says.
Kinetic LAL assay against the < 0.05 EU/mg release limit — the test that matters most for cell-culture work.
ICP-MS screening for catalyst and process residues across the periodic table.
Headspace GC against ICH Q3C limits for the solvents used in synthesis and purification.
Total aerobic microbial count and sterility indicators on the fill/finish environment and final lyophilizate.
How batch verification works
- Sample at release. A retained sample is pulled under classified conditions at the end of manufacturing — before anyone knows the results.
- Blind-code and split. The sample is relabelled with a code that hides the identity and expected values, then split between our lab and North Analytics.
- Run the panel. The external lab runs its own instruments and methods; our QA team runs the internal release tests in parallel.
- Reconcile. Both result sets must meet the release specification. Any out-of-specification result stops the lot — it is investigated, documented and either reprocessed or rejected, never quietly retested until it passes.
- Publish. Only lots that pass both tracks get a certificate of analysis with the batch number that ships on your vial.
| Test | External method | Runs |
|---|---|---|
| Purity | Gradient RP-HPLC | Every batch |
| Identity | LC-ESI-MS | Every batch |
| Endotoxins | Kinetic LAL | Every batch |
| Heavy metals | ICP-MS | Every batch |
| Residual solvents | Headspace GC (ICH Q3C) | Every batch + process changes |
| Stability pulls | Full panel, comparative | Quarterly against retention samples |
Where results appear
Results are published on the certificate of analysis linked from every product page's COA tab, and summarized in the current batch register. The issuing lab, method and batch number appear on each certificate — the same three fields shown on the product pages.
If your re-test disagrees
Run it in duplicate, and check that your solvent system and column chemistry match the method noted on the certificate — most apparent mismatches are method differences, not material differences. If the discrepancy remains, send the batch number and your chromatogram to qc@peptidekontor.com or through the contact form. Every reported discrepancy triggers a documented investigation covering retained samples and raw data, with a replacement or full refund if our certificate is wrong.