Isotopically labelled peptides
Also known as: stable isotope labelled internal standard · SIL peptide
Peptides synthesised with heavy isotopes, typically carbon-13 and nitrogen-15, used as internal standards in quantitative mass spectrometry.
Development status: Laboratory research reagent
Identifiers and molecular characteristics
- CAS number
- Not verified
- Molecular formula
- Not verified
- Molecular mass
- Not verified
- Amino-acid sequence
- Not verified
- PubChem CID
- Not verified
Identifiers are published only with a source and a check date. Fields marked “not verified” have not yet been confirmed against a primary source — we show the gap rather than an unchecked figure. Always confirm against the certificate of analysis for the specific lot you hold.
Biological targets
- Not applicable — these are measurement materials
Mechanism of action
A labelled peptide behaves almost identically to its unlabelled counterpart during sample preparation and chromatography but is resolved by mass. Spiking a known amount lets the analyst correct for losses and ionisation variability, which is what makes the quantitation trustworthy.
Research evidence and its limits
Standard practice in quantitative proteomics and bioanalysis, codified in regulatory bioanalytical method validation guidance.
Safety considerations
No regulatory authority has assessed this compound as safe or effective for any human indication. The published record is predominantly laboratory and animal work, which does not establish human safety. Supplied and discussed here strictly as a laboratory research material. Not a medicine, not for human or veterinary administration, and nothing on this page should be read as a dosing, treatment or safety recommendation.
Analytical identification and quality testing
Identity by high-resolution mass spectrometry against the expected mass, purity by RP-HPLC with UV detection. Tandem MS sequencing or peptide mapping gives stronger identity evidence than mass alone.
Regulatory status
Laboratory materials, not medicines.
References
Related compounds
Entry last reviewed 2026-10-11. Regulatory status and scientific understanding change; verify against primary sources before relying on anything here.