Guide for Research Suppliers
The pre-release QC checklist every research peptide supplier should run.
If you sell research-grade peptides, the quality of your QC program is the quality of your brand. This is the analytical checklist we recommend before any lot leaves your facility — what to test, why it matters, and where independent third-party testing replaces internal-only data.
1. Lock down a batch identifier at receipt
Every incoming lot from your synthesis partner gets a unique batch ID before anything else happens. That ID stays attached to the material through every assay, every retain sample, and the final COA. Without it, traceability collapses.
2. Identity by LC-MS, every batch
Don't assume the label is right. Run electrospray LC-MS in positive mode (and negative when needed) and compare observed mass to the theoretical monoisotopic mass. ±0.01 Da is a reasonable acceptance window for short-to-medium peptides.
3. Purity by reverse-phase HPLC
C18 column, water/acetonitrile gradient with 0.1% TFA modifier, UV detection at 214 nm. Report area-percent of the main peak and integrate every related impurity above the 0.1% reporting threshold. Release the chromatogram, not just the number.
4. Water content by Karl Fischer
Lyophilized peptides absorb water. KF coulometric titration gives an accurate water number, which feeds into assay-corrected active content. Skipping this step inflates apparent dose accuracy.
5. Bacterial endotoxin by LAL
Kinetic chromogenic LAL per USP <85> with a detection limit at or below 0.005 EU/mL. Endotoxin contamination is invisible visually and the dominant safety failure mode for any injectable-route research material.
6. Residual solvents by HS-GC-MS
Headspace GC-MS per USP <467> for ICH Q3C Class 1, 2, and 3 solvents. Synthesis residue varies batch-to-batch even from the same supplier; spot-checking is not enough.
7. Net content & assay-corrected mass
Verify the actual mass of peptide per vial against label claim, corrected for water and counter-ion content. The number on the vial should match the number in the bottle.
8. Independent third-party COA
A COA generated by your own QC team is a starting point. A COA from a lab with no commercial interest in the result is what downstream buyers actually trust. Use a third-party lab for at least your release panel.
9. Public verification anchor
Every batch ID should resolve to a public record at the testing lab — not your website, not a PDF on a CDN. The verification path should be controlled by the lab that did the work, so a forged certificate has nowhere to land.
10. Retain samples and raw data
Hold a portion of every released batch at -20°C for at least 12 months. Make sure your testing lab retains raw chromatograms and spectra for at least 3 years. Both are non-negotiable when a customer escalates a complaint.
In practice
Where SteriGenix fits in.
SteriGenix is the third-party analytical lab a lot of US research-compound suppliers use for their release panel. A typical engagement runs HPLC purity + LC-MS identity + LAL + Karl Fischer + residual solvents on every released batch, with the certificate anchored to a public batch ID on the Verify portal. Pricing and turnaround are published on the Pricing page.
Talk to the lab.
Volume pricing, white-label COA formats, and onboarding for ongoing release-panel programs.
Contact the Lab