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What are endotoxins in peptides?
The short answer
Endotoxins are heat-stable fragments of bacterial cell walls that can remain in a product even after sterilisation kills the bacteria. They are detected by a dedicated assay, usually LAL, and not by chromatography — a peptide can be chromatographically immaculate and still carry a significant endotoxin load. Purity testing tells you nothing about it.
In detail
The point is that sterility and endotoxin content are different questions with different answers. Autoclaving destroys organisms but leaves endotoxin intact, so a sterile sample is not automatically a low-endotoxin one.
Endotoxin testing is priced separately wherever it is offered, because it requires different reagents, controls and expertise from chromatography.
Our published tariff covers purity, quantification and identity. Where a question falls outside that scope, the certificate says so rather than implying coverage we did not provide.
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