Glossary
Certificate terms, explained
What the tests on a peptide certificate of analysis measure, what they don't, and how PeptideAudits reads each one. PeptideAudits doesn't test products; it inspects certificates that sellers publish.
HPLC purity
The share of the UV-detected peak area that belongs to the target peptide. It describes how clean the sample looks under that method, not how much peptide the vial holds.
Read explainer →Endotoxin
Lipopolysaccharide (LPS) from the outer membrane of gram-negative bacteria, reported in endotoxin units (EU). It can remain in a sample after the bacteria are dead.
Read explainer →Sterility
A test (for example USP <71>) for whether viable microorganisms grow from the units tested. It is different from a PCR or microbial-count screen.
Read explainer →Batch-number reuse
The same batch or lot number, or identical results, appearing on certificates that look like separate tests. It's worth comparing against the lab's own record.
Read explainer →
For a walkthrough of a full certificate, see the COA guide. For research use only; not medical advice.