Peptide Purity

The percentage of the target peptide compound in a sample relative to all other components, measured by HPLC. Research-grade peptides are generally ≥98% pure by HPLC analysis. Common impurities include amino acid deletion sequences (missed couplings during synthesis), oxidized side chains (particularly methionine and cysteine), protected amino acid residues from incomplete deprotection, or aggregated fragments. Purity data is documented in the Certificate of Analysis (COA) that reputable manufacturers provide for each batch.