Stable isotope labeled peptides, maintain identical amino acid sequence with the natural ones released from the parent proteins by chemical or enzymatic cleavage, but some of the amino acid residuals are labeled by specific stable isotope, such as ²H, ¹³C, and/or ¹⁵N atom(s).

Stable isotope labeled peptides have been widely applied in the nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). The combination of sable isotope labeled peptides with NMR spectroscopy allow for the incorporation of NMR active nuclei which can reduce the complexity of spectra, and then help researchers to obtain novel correlations between atoms for more structural information. Meanwhile, the utilization of sable isotope labeled peptides in quantitative proteomics can facilitate the comparison of different proteomes, and protein-protein interaction studies as internal standards, even MRM/SRM-based absolute quantification of specific target proteins in biological samples. This AQUA strategy is quite useful in protein therapeutics discovery, pharmacokinetics, and toxicity studies, etc. And all the quantitative services can be provided by our analytical professionals as well, if you require.