Every peptide we sell is supplied with a certificate of analysis (COA) for its batch. This page explains what the certificate shows and how to read it.
What a certificate of analysis shows
- Identity, confirmed by mass spectrometry (MS): the measured molecular mass should match the expected mass of the peptide.
- Purity, measured by high-performance liquid chromatography (HPLC): the percentage of the sample that is the target peptide, shown as the main peak on the chromatogram.
- Batch number and test date, so the certificate can be matched to the batch you receive.
- Appearance of the lyophilised material, for example white or blue powder.
How to read the purity figure
HPLC separates the components of a sample, and each appears as a peak on a chart. Purity is the area of the main peak as a percentage of the total. A higher figure means fewer related impurities, such as truncated or incomplete sequences from synthesis.
How to read the identity result
Mass spectrometry measures the mass of the molecule. The certificate lists the expected (theoretical) mass alongside the observed mass. A close match confirms the sample is the stated peptide.
Getting the certificate for your batch
Certificates are published on each product page as they become available. If you would like the certificate for the current batch before you order, contact us and we will send it to you.
Storage after delivery
Lyophilised peptides are most stable stored sealed at −20 °C, protected from light and moisture. Storage details for each product are listed on its product page.