Proteomics



Mass spectrometry (MS)-based proteomics has become an essential tool for biologists over the last decade. The ability of a mass spectrometer to identify thousands of proteins from a complex biological sample has revolutionized scientific experiments. To fully understand the function of the proteome in health and disease, however, one must have the ability to accurately quantify proteins in many different types of biological samples. The invention of faster and higher resolution mass spectrometers has enabled the quantification of complex proteome dynamics. Heavy stable isotopes are routinely employed to generate precise and accurate quantitative proteomic data. Peptides labeled with heavy stable isotopes share identical biochemical characteristics to “light” or unlabeled peptides except for a difference in mass. Mixing heavy peptides with light peptides results in peptide pairs that co-elute into the mass spectrometer, which can easily distinguish between the peptides based on the mass difference. Quantifying differences between proteomes subjected to different biological conditions or experiments can be achieved when using the heavy peptides as an internal standard or a control. CIL offers a variety of stable isotope reagents for labeling any proteome for quantitative MS analysis. These stable isotope MS methods are bringing scientists closer to curing human diseases through quantitative biomarker analysis and quantitative proteomic analysis of animal models of disease.

 

 

Click here to download a technical note on Mass Spectrometry Signal Calibration for Protein Quantitation, written by Michael J. MacCoss, PhD, Associate Professor of Genome Sciences, University of Washington, School of Medicine.
 

Click here to download a technical note on Early Stable Isotope Labeling in Proteomics, written by Timothy D. Veenstra, PhD, NCI

 

 

Metabolic Labeling

Metabolic Labeling

One type of proteome labeling introduces a stable isotope amino acid(s) to cell growth media or rodent feed. Growth and feeding periods allow the stable isotope-labeled amino acid(s) to become metabolically incorporated into the proteome. Learn more.
Chemical Labeling

Chemical Labeling

Isotopically labeled standards for proteomic measurements can be prepared chemically. This can be achieved at the peptide or protein level by solid phase synthesis or recombinant gene expression, respectively. Learn more.
QC and Quantitation Kits

QC and Quantitation Kits

To help expedite quality control (QC) and quantitation in proteomics, CIL offers a number of off-the-shelf kits. In general, the QC kits are designed to evaluate the performance of the LC-MS platform, either alone or in combination with the analytical workflow. Learn more.
Chemical Tagging

Chemical Tagging

Chemical tagging refers to labeling proteins or peptides in vitro. This inexpensive method is advantageous over metabolic labeling due to its ability to label human samples and its low cost. In addition, chemical tagging can quantify more than two samples in one MS experiment. Learn more.
Enzymatic Labeling

Enzymatic Labeling

The incorporation of two 18O atoms into each C-terminus of peptides derived from proteolytic digestion of biological samples has emerged as one of the leading global labeling strategies used in comparative quantitative proteomics. Learn more.
Application | Cambridge Isotope Laboratories, Inc.