Heavy Isotope Labeling

Isotopically labeled peptides

Stable-isotope labeled peptides are used in biomarker discovery and validation as well as in drug and metabolite monitoring, peptide signaling experiments, metabolomics and pharmaco kinetics. Bio-Synthesis, Inc is pleased to supply scientists and researchers with custom synthesized stable-isotope peptides. In contrast to standard amino acids, isotopically labeled amino acids are synthesized by substituting 12C, 14N, and H atoms with 13C, 15N, or Deuterium atoms. These amino acids are non-radioactive and have known molecular weights that are higher than standard amino acids. This molecular weight difference makes stable isotope labeled peptides useful tools for quantitative peptide analysis or protein structure and dynamics determination by mass spectrometry (MS) or nuclear magnetic resonance (NMR) spectroscopy, respectively. When used as surrogate markers for proteins of interest, these peptides are added to allow proteins that they represent to be quantified. The best markers/internal standards are peptides that have exact sequences as the biomarker peptides and carry stable isotopic labels. The isotopes change the mass but not the chemical behavior. Isotope ratio of spiked peptides and peptides obtained from protein biomarkers are measured by mass spectrometry and tandem mass spectrometry to provide absolute quantitation of proteins of interest. Stable-isotope labeled peptide sequences are synthesized using the latest Fmoc solid-phase technology and purified by HPLC. All stable-isotope labeled peptide sequences come with certificate of analysis, mass spectrometric analysis and, stringent analytical HPLC to determine the final purity and assure that you are receiving only the highest quality peptides for absolute quantitation.