Topic / Measurement records
Check that a peptide listing and its test results trace back to a defined identity, an accredited laboratory and a documented reference standard.
Fix the identity of the material first. The CAS, sequence and molecular weight guide shows how to confirm that a listing describes the peptide you intend to buy, because every later check depends on comparing results against the right reference values.
Then check who produced the measurements and against what. The ISO 17025 guide explains how to confirm a laboratory's accreditation and whether its scope covers the test reported, and the traceability guide explains what a traceable reference-standard claim must show to mean anything.
Read the amino acid analysis guide when you need net peptide content or composition, rather than purity alone, recorded for your lot.
Measurement records
A six-point check, drawn from NIST policy, for deciding whether a supplier or lab traceability claim is usable or just a label.
7 min read · Research guide
Measurement records
Check that a third-party testing laboratory is accredited by a recognized body, that the accreditation is current and that the specific test on your certificate is within its scope.
6 min read · Research guide
Measurement records
Cross-check a product page against PubChem and CAS: sequence, formula, molecular weight and salt form, with a worked mismatch using angiotensin II and how to log it.
7 min read · Research guide
Measurement records
What amino acid analysis measures, how it yields net peptide content and a composition check, which residues it cannot recover reliably, and why research-peptide certificates rarely include it.
8 min read · Research guide
Measurement records
A glossary of terminal and side-chain modifications with their notation and exact mass change, a worked example showing why an amide and a free acid are different compounds, and the questions to send a supplier.
8 min read · Research guide
Measurement records
A reference table of the 20 standard amino acids with one- and three-letter codes and residue masses, the IUPAC rules for termini and D-residues, and a worked check of a supplier sequence against UniProt.
8 min read · Research guide
Measurement records
What each chemical identifier system is, who assigns it, what it proves and what it does not, with an oxytocin cross-walk showing how salt forms and synonyms split one peptide across several records.
8 min read · Research guide
Measurement records
What a chain-of-custody record contains, how sealing and photos protect it, how two example laboratories' submission requirements work, and how to tie the result back to the lot record, with a form template.
8 min read · Research guide