Peptide purity testing is typically performed using analytical HPLC as the primary method, often supported by mass spectrometry for identity confirmation. In an HPLC purity assay, the peptide is separated from closely related impurities such as truncation products, deletions, or side products, and the main peak area is compared with total detected material.
Common QC elements
- HPLC chromatogram to assess purity profile
- MS data to verify molecular weight
- COA listing purity value, lot number, and test method
- Method details such as column type, solvent system, and detection wavelength
For research procurement, the most useful documentation is a current certificate of analysis tied to the exact lot received. Laboratories should also confirm that the supplier specifies the analytical method used, because purity values can vary depending on whether the result is based on reverse-phase HPLC, area normalization, or another validated approach.
Research peptides are intended for laboratory research use only and are not intended for human consumption.