Purity is not content
HPLC purity is the main peak relative to everything that absorbs UV; it ignores water and salts. The amount of desired peptide is content multiplied by purity.
Quality
No single test proves a compound.
Each method answers one question, and knowing which question is the difference between a supplier’s claim and a verified batch.
Four points we stand on
Necessary, not sufficient
HPLC and LC-MS come first on every batch. For a novel compound they do not settle structure or content on their own.
Content without a standard
qNMR measures content without a reference standard of the compound. Amino acid analysis and elemental analysis are the traditional alternatives.
NMR where it is warranted
For novel compounds and unusual building blocks it is the real confirmation of structure. Established compounds with a proper reference standard do not always need it.
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Purity is not content
A purity figure says how clean a peptide is, not how much of it is in the vial. One vial, worked through.
ReadReference standards
A measured value is only as good as what it is measured against. For a new compound, we build the reference first.
ReadAnalytical methods
Ten methods, each answering one question: when we use them, and the limit of each one, stated honestly.
ReadWhat goes wrong at the supplier
Five patterns from our own supplier work, how they show up in the material, and how we catch them.
ReadThe route is decided by the molecule
Solid phase, solution phase or a hybrid: why the route depends on the molecule, and what it says about a supplier.
ReadHPLC purity
How HPLC separates a sample, how purity is calculated from the chromatogram, and what the figure does not tell you.
ReadEndotoxin testing
What endotoxins are, why they matter for material used on cells, and how they are measured.
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Questions about a compound?
Whether you need a niche compound sourced or a private synthesis organised, or want to work with us as a supplier or laboratory, tell us what you are working on.
Talk to us