Understanding peptide purity

Purity is measured per batch, not per product line. What you want from a supplier is a process that produces the same result every time, rather than one good batch followed by an unknown one.

HPLC purity tells you the percentage of the desired peptide relative to other peaks in the chromatogram. Mass spectrometry (MS) confirms the molecular weight. Together they establish identity and approximate purity.

Residual solvents, heavy metals and microbial contamination are the other things worth controlling. Where the supplier manufactures in its own laboratory, those controls sit inside the production process rather than being checked after the fact.

Peptitrust peptides are made and tested in our own laboratory, with in-house HPLC testing on every batch to a minimum of 99% purity before release.