Introduction

    In recent years, the introduction of isotope-coded affinity tags (ICAT) greatly expands the applications of mass spectrometry (MS) for research in proteomics¹.  The difference of molecular weight between isotope labeled and non-labeled reagents allows researchers to measure the relative amounts of proteins or peptides in complex samples. This technique has been used for simultaneous identification and quantification of individual proteins and for determining changes in the level of phosphorylation at specific sites².  A review article by Dr. Aebersold has been very useful³.  

N15 and C13 Isotope Labeled Peptides 

      Due to the potential of isotope reagents for various applications, Princeton BioMolecules has introduced the services of synthesis of non-radioactive isotope labeled peptides to research communities.  Two major isotopes - N15 and C13 - are implanted in a specific amino acid of peptides.  Each atom contains over 99% enriched isotope and it can be at more than one position in peptide.  For example, a Leu amino acid can contain one N15 and six C13; and a peptide containing one such isotope labeled Leu amino acid will have seven units of molecular weight higher than the corresponding peptide without isotope labeled.  This kind of peptide can be used in many biological research areas, especially in genomics, as an internal standard for quantification in combination with MS.

     If you think N15/C13 labeled peptides are useful in your research, please contact us.  We would like to discuss  your  requirements and specifications of experiments and design a reasonable synthesis strategy to make a suitable reagent for you.

References:

1. Steven P. Gygi et. al. "Quantitative analysis of complexes protein mixture using isotope-coded affinity tags", Nature Biotechnology, 17:994-999, 1999.

2. Y. Oda, K. Huang, F.R. Cross, D. Cowburn, B.T. Chait, "Accurate quantitation of protein expression and site-specific phosphorylation". Proc. Natl. Acad. Sci. USA, 96:6591-6596, 1999.

3. R. Aebersold, D.R. Goodlett, "Mass spectrometry in proteomics", Chemical Review. 101: 269-295, 2001.

(NOTE: N15 and C13 are not radioactive.  It is safe to use.)

 Back to Home Page        Contact Us