Stable Isotope Peptides

Advanced Peptides specialises in the rapid synthesis of peptides containing stable isotope labelled amino acids.

By using stable-labelled versions of tryptic peptides as internal standards, it is possible to directly quantify protein levels in a digested sample via mass spectrometry.

Critical to the accuracy of this technique is the quality of the stable-labelled peptide. CRB’s custom stable–labelled peptides are offered:

• Critical to the accuracy of this technique is the quality of the stable-labelled peptide.
• >95% pure by HPLC
• analysed for net peptide content.

For the quantitation of post-translational modifications, CRB can also offer stable-labelled peptides containing:

• phosphoTyr, phosphoSer, phosphoThr
• sulfoTyr
• methylated Lys and Arg

Isotopically labelled versions of peptides derived from proteolysis by other enzymes, such as Lys-C, Glu-C, can also be produced.

Our standard stable-isotopically labelled amino acids provide the greatest shift in the molecular weight for the least cost; however, heavy atom versions of other amino acids are available upon request.