Peptide Terms Explained
Short answerA short glossary of the words you will see on peptide labels and COAs: lyophilized, HPLC, mass spectrometry, lot number and more.
- Lyophilized
- Freeze-dried. The standard dry, stable form of research peptides.
- HPLC
- High-performance liquid chromatography, the method used to measure purity.
- Mass spectrometry (MS)
- Confirms the molecular weight, so you know the right molecule is in the vial.
- COA
- Certificate of Analysis, a lab report for a specific lot.
- Lot number
- The batch identifier. It should match between the vial and its COA.
- Bacteriostatic water
- Sterile water with a preservative, used as a diluent in laboratory work.
- Sequence
- The order of amino acids in the peptide.
More on testing: Lab Testing & COAs.
Frequently Asked Questions
What is HPLC?
HPLC (high-performance liquid chromatography) is the laboratory method used to measure a peptide's purity.
What is a COA?
A COA, or certificate of analysis, is a laboratory report for a specific lot. It lists purity, identity and the lot number, which should match the vial.
What is bacteriostatic water?
Bacteriostatic water is sterile water containing a preservative, benzyl alcohol, that limits bacterial growth. It is commonly used as the diluent when reconstituting freeze-dried peptides.
Related articles
- I'm New to Peptides: Where Do I Start?
- Why Are Peptides Supplied as a Powder?
- Peptide Storage: Lyophilized and Reconstituted Guidelines
- Peptide Measurement Guide: mg, mcg and Units
Educational resource only. This information is not medical or legal advice, and Peptide Authority does not offer peptides or any products for use.