18O Protein Expression

Provides accurate quantitative information about response to stimulation. Determines ration of individual protein expression level between two samples relative to teach other, therefore ideal for pairwise comparisons.


  • Can apply to virtually any sample type including clinical samples
  • Peptides labeled by 16O and 18O co-elute from the reverse phase chromatographic column which allows for accurate quantification by LC-MS
  • Amendable to low sample concentration (600 ng for LC-MS/MS)


  • Only two samples can be compared to each other at one time
  • Difficulty accommodating complex experimental design

Contact Person:

Masaru Miyagi, Ph.D. (masaru.miyagi@case.edu)
Center for Proteomics and Bioinformatics
Case Western Reserve University
10900 Euclid Ave., BRB 928 Cleveland, OH 44106-4988
Phone: 216- 368-5917 Fax: 216-368-6846

18O Labeling Review

Miyagi, M. et al. Proteolytic 18O-labeling strategies for quantitative proteomics. Mass Spectrom. Rev.,2007;26:121.136. doi: 10.1002/mas.20116

Center Paper

Hajkova, D., Imanishi, Y., Palamalai, V., Rao, K. C., Yuan, C., Sheng, Q., Tang, H., Zeng, R., Darrow, R. M., Organisciak, D. T., and Miyagi, M. (2010) Proteomic Changes in the Photoreceptor Outer Segment upon Intense Light Exposure, J Proteome Res 9, 1173-1181.

Relative Quantification

Absolute Quantification