Third-party testing is independent verification of a supplier’s analytical claims. This article explains how it differs from internal quality control, what to look for in an independent COA, and how to evaluate the testing laboratory itself.
What third-party testing is
Third-party testing is analysis performed by a laboratory that is organizationally independent of the supplier. The independent laboratory receives a sealed sample, runs its own methods, and issues its own report. The supplier does not influence the result.
Why it matters
Internal QC can be honest and still be wrong, biased by method choice, or vulnerable to undetected calibration drift. Independent verification eliminates the closed loop and turns reported numbers into auditable facts.
Evaluating the testing laboratory
Look for accreditation (for example, ISO/IEC 17025), a published scope of methods, and a track record of work in peptide analysis. An accredited laboratory operating outside its scope of accreditation is not the same as an in-scope accredited result.
