Articles on the analytical methods behind a certificate, how to read the documents that arrive with a lot, and how laboratory material behaves on the bench. Written for laboratory context only — no compound here is described in terms of use in humans or animals.
A purity percentage is the most quoted number on a peptide certificate and the most widely misread. This is what the measurement is, and what it is not.
A certificate of analysis is a record of specific tests performed on a specific batch on a specific date. Read line by line, it tells you a great deal — and it stops well short of everything.
Most avoidable variability in peptide work is introduced before the first measurement, during storage and handling of the dry material.
The same peptide can appear under a code name, a sequence, a trade designation and a registry number. Knowing how those identifiers relate makes catalog entries checkable.
More articles are in preparation. Nothing is published here until every claim in it can be traced to a document that genuinely exists.