Does every research peptide in the catalogue have a disulfide?

No. Infer a bridge only from a sequence that contains cysteine and from a mass species the report names. A product title is not that evidence.

Is a disulfide the same as a peptide bond?

No. A peptide bond links residues along the chain. A disulfide is a side-chain S–S bond. They are different links.

Glossary · 2026-09-24

Scientific lead: Alice Kay, Ph.D.

Disulfide bridge, laboratory definition

A disulfide bridge is a covalent bond between two sulfur atoms, usually the side chains of two cysteine residues. It can close a ring in one chain or tie two chains together. It changes the mass relative to two free thiols, so an identity calculation has to state whether the cystines are bridged. This glossary does not assign that form from a product name.

The BPC-157 sequence published on this site, GEPPPGKPADDAGLV, contains no cysteine, so that string does not describe an intramolecular disulfide. Read sequence and bonding in peptide structure and stability and structural peptides. Confirm any bridge only when the lot file's mass species says so. 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

Does every research peptide in the catalogue have a disulfide?: No. Infer a bridge only from a sequence that contains cysteine and from a mass species the report names. A product title is not that evidence.
Is a disulfide the same as a peptide bond?: No. A peptide bond links residues along the chain. A disulfide is a side-chain S–S bond. They are different links.

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. The biochemist of record is Alice Kay, Ph.D.