What is a peptide?

Why does the COA matter?

A certificate of analysis documents lot identity and purity with analytical methods. PACO presents it as verified only when the corresponding PDF is published.

Without a PDF, we show no verified purity; tap Notify me and we email you when it is published. That does not imply a clinical result or a use.

What does >99% purity mean?

On a COA, a purity figure describes the fraction of the sample the laboratory attributes to the target sequence versus other signals.

It is analytical data. It does not establish dosing, effect, or a use in humans or animals.

How do you read a certificate of analysis?

A typical COA names the compound, lot identifier, methods (HPLC, mass), and published results.

Each PACO lot links its own certificate when the PDF is available. If there is no PDF, there is no download and no verified seal.

What is the difference between a peptide and a protein?

A peptide is a short chain of amino acids joined by peptide bonds. A protein is longer and usually folds into a three-dimensional structure.

Peptides are distinguished by sequence, length, molecular mass, and chemical modifications. Those properties describe the molecule; they do not establish a clinical use.

Solid-phase synthesis made defined sequences routine to prepare. Insulin was the first peptide isolated for therapeutic use, in 1921.

Why measure with HPLC?

High-performance liquid chromatography separates sample components to examine identity and purity. Mass spectrometry complements that reading.

What is a lot, and why is it traced?

A lot is one preparation made together. Tracing ties each vial to that record and, when it exists, to that lot's PDF.

Notify me means the document is not published yet; it does not imply completed purity, identity, or verification.