Research peptide glossary A to Z
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This glossary defines 24 terms that appear on research peptide listings and certificates of analysis, in alphabetical order. Each entry is a general chemistry definition. Compound-specific details are in the individual guides, such as the BPC-157 guide.
Glossary at a glance: terms A to F
| Term | Meaning |
|---|---|
| Acetate | A common counter-ion paired with a peptide in its salt form. |
| Amino acid | A building block of peptides and proteins. |
| Analogue | A compound with a structure closely related to another, with one or more changes. |
| Batch number | The identifier linking a vial to its certificate of analysis. |
| Blend | A single vial containing more than one compound, premixed. |
| CAS number | A unique numeric identifier for one chemical substance. |
| COA | Certificate of analysis: the batch document reporting test results. |
| Counter-ion | An ion paired with a peptide in its salt form. |
| Cyclic peptide | A peptide with a ring formed by an extra bond in the chain. |
| Fragment | A shorter piece of a longer peptide or protein sequence. |
What do terms H to P mean?
| Term | Meaning |
|---|---|
| HPLC | Liquid chromatography, a method that separates a sample into components and reports purity. |
| Linear peptide | An open chain of amino acids with no ring. |
| Lyophilised | Freeze-dried; water removed from a frozen material under vacuum. |
| Mass spectrometry | A method that measures molecular mass, used to confirm identity. |
| Molecular weight | The mass of one mole of a compound, in g/mol. |
| Net peptide content | The share of the vial mass that is the peptide itself. |
| Pentapeptide | A peptide of five amino acids. |
| Peptide | A chain of amino acids joined by peptide bonds. |
| Purity | The proportion of a sample that is the target compound, usually reported by HPLC. |
What do terms R to V mean?
| Term | Meaning |
|---|---|
| Residue | One amino acid unit within a peptide chain. |
| Salt form | The compound combined with a counter-ion, such as acetate. |
| Sequence | The order of amino acids in a peptide, written from one end to the other. |
| Tripeptide | A peptide of three amino acids. |
| Vial | The sealed glass container in which a material is supplied. |
What should the documentation show?
- Terms on the listing match those on the certificate.
- The CAS number and batch number are present.
- Purity and mass results are reported.
Batch documents are on the COAs page. See also what is a CAS number and peptide purity explained.
Frequently asked questions
What is the difference between a peptide and a protein?
A peptide is a short chain of amino acids. There is no strict cut-off, but longer chains of many dozens of residues are usually called proteins.
What is a pentapeptide?
A peptide made of five amino acids.
What does COA stand for?
Certificate of analysis. It is the document reporting the test results for a specific batch.
What is an analogue?
A compound whose structure is closely related to another, with one or more deliberate changes.
What is a residue?
One amino acid unit inside a peptide chain. A tripeptide has three residues.
All Ascend Research products are sold strictly for laboratory research use only. They are not for human or animal use, and nothing in this article is medical advice.
The Ascend Research team