Purity
Also known as: peptide purity · 99% purity · 98% purity
The percentage of a sample that is the intended peptide, as measured by HPLC — the headline quality figure.
Purity is the proportion of a sample that is the intended compound rather than by-products, truncated sequences, salts or residual solvents. It is expressed as a percentage and measured by HPLC.
Research-grade peptides are typically characterised at 98%+ purity. Higher purity means fewer confounding impurities in research and more consistent results between batches.
Purity is meaningful only when it is measured and documented — which is exactly what the HPLC figure on a Certificate of Analysis provides. Purity (from HPLC) and identity (from mass spectrometry) are the two headline quality metrics.
RELATED TERMS
HPLC
High-Performance Liquid Chromatography — the standard technique for measuring the purity of a peptide.
Mass Spectrometry
An analytical method that measures a molecule’s mass to confirm a peptide’s identity matches its intended sequence.
Certificate of Analysis (CoA)
A batch-specific lab document reporting a compound’s identity and purity — the primary proof of what is in the vial.
Acetate Salt
The salt form peptides are supplied as; net peptide content is slightly below the raw weight because of the counter-ion.
Educational content, not medical advice. All products supplied for research purposes only — not for human consumption.