Glossary · 2026-09-24
By Alice Kay · Last reviewed 24 Sep 2026
C-terminus of a peptide chain
Research-use notice: This article summarizes published scientific literature for educational purposes. It is not medical advice and does not provide dosing, administration or human-use information. Findings described in the literature do not apply to any BlueNex Labs product, which is supplied only for in-vitro laboratory research and not for human or animal use.
The C-terminus is the end of the chain opposite the N-terminus. It may be a carboxylic acid or an amide. Those forms are different species, so a calculated mass has to follow the form the report names. Amidation is the glossary entry for the amide case. It is not a purity unit.
Do not flip a sequence to put the C-terminus first, and do not assume an amide because a trade name sounds modified. Read the species line on the PDF, then the sequence as published. For the structure discussion, see peptide structure and stability. Research use only.
Published lot files for this catalogue are indexed in the certificates library. This definition does not add a report, and it does not assign a task identifier. Research use only.
Frequently asked questions
- Is the C-terminus always an amide on research peptides?
- No. Acid and amide are both possible. Use the form written on the lot file. If it is absent, do not choose one.
- Does the C-terminus appear in the shop URL?
- No. The URL carries a catalogue name and often a milligram size. End-group chemistry belongs on the sequence note or the report.
Research use only. BlueNex Labs does not provide medical or veterinary advice. Confirm your institution’s policies before purchase. How a comparison or class note is checked sits on documentation standards. Articles are written and reviewed by Alice Kay, Ph.D.