Research
Reading the paperwork
References on the analytical chemistry behind a certificate of analysis — what each test measures, what it cannot establish, and how to check a supplier's figures against their own document.
These pages are about method, not about products. Nothing here describes what a compound does, and nothing here is a usage guide. They exist because the numbers on a certificate are quoted constantly in this market and explained almost nowhere, which makes them impossible to compare and easy to invent.
12 min read
How to read a peptide certificate of analysis
A certificate answers three questions using three tests - is this the right molecule, how clean is it, and how much is actually here. Most skip the third.
11 min read
HPLC purity vs net peptide content
Neither number is a property of the material. Both are properties of the method - so two labs can analyse one vial, differ, and both be correct.
9 min read
Mass spectrometry for peptide identity
A mass spectrum confirms the material weighs what the claimed molecule should weigh. That is not the same as confirming the sequence.
7 min read
What a certificate of analysis does not establish
HPLC and mass spectrometry characterise a molecule. They are silent on sterility, pyrogens, catalyst metals and synthesis solvents.
6 min read
Why lot-specific testing matters
Peptide synthesis is stepwise, so small variations compound. A certificate for one batch tells you very little about the next.
6 min read
Peptide counterions and salt forms
Almost every synthetic peptide is a salt, not a free base. The counterion is a large fraction of what you weigh, and it is not inert in cell work.
7 min read
Lyophilisation and peptide stability
Freeze-drying stabilises peptides by removing the mobile water most degradation needs. That explains every storage rule, and why they change on reconstitution.
6 min read
How to evaluate a peptide supplier
A twenty-five point rubric for any supplier in this market, including us. It scores documentation and claims discipline - the only things a buyer can verify.
Our own certificates