Every Peptide Spot product is tested by independent U.S.-based laboratories. Batch-specific Certificates of Analysis confirm purity and identity before any product ships.
Peptides are manufactured by U.S.-based laboratories using solid-phase peptide synthesis (SPPS)
Reversed-phase HPLC determines purity percentage. We require ≥98% for all products
ESI-MS or MALDI-TOF confirms the molecular weight matches the expected peptide identity
A batch-specific Certificate of Analysis is generated and included with your order
In research, reproducibility depends on reagent quality. A peptide that isn't what it claims to be — or contains significant impurities — can invalidate months of work. Third-party testing by independent laboratories eliminates vendor self-reporting bias and provides objective quality verification.
Our testing partners are independent of our supply chain. They have no financial incentive to inflate purity numbers. This separation between manufacturing and testing is the gold standard in analytical quality assurance.
Every order ships with a batch-specific Certificate of Analysis. Need a COA before ordering? Contact us with the product name and we'll provide it.
Request a COAYes. Every order ships with the batch-specific COA for each peptide in your order. The COA is matched to the exact lot number of your product.
Absolutely. Email us at support@peptide.spot with the product name and we'll send the current batch COA within 24 hours.
Testing is performed by independent, U.S.-based analytical laboratories that are not affiliated with our peptide manufacturers. This ensures unbiased, objective results.
All peptides must meet a minimum of ≥98% HPLC purity. Most of our products test at ≥99%. Any batch falling below our threshold is rejected and not sold.
We've written a detailed guide: Understanding HPLC and Mass Spec Purity Testing. It explains how to interpret chromatograms, mass spectra, and identify red flags.