Glossary · 2026-09-24
By Alice Kay · Last reviewed 24 Sep 2026
Linear peptide, laboratory definition
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.
A linear peptide is an open chain of residues, written from the N-terminus to the C-terminus, without a ring implied by the string itself. Epithalon is catalogued as Ala-Glu-Asp-Gly on the 10 mg listing. BPC-157 is published as GEPPPGKPADDAGLV, with no cysteine, on What is BPC-157? and the 10 mg listing.
Calling a string linear does not replace a mass match. A later lot file could still name a modified species. Do not add a ring, an amide, or a salt that the PDF does not name. Compare language is on BPC-157 versus TB-500, which separates those sequences. Research use only.
Frequently asked questions
- Is a linear sequence the same as a purity result?
- No. The sequence is the residue order used for a calculation. Purity is the area percent when the report includes one.
- Does the absence of cysteine prove there is no other ring?
- It rules out an intramolecular cystine bridge in that string. Other end-to-end modifications still have to be read from the lot file, not assumed.
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.