Protein quantification and quantitative assessment of multiple post-translational modifications (PTM) within a single protein are becoming increasingly important in the biomarker discovery, validation, and proteomic studies. Mass spectrometry (MS) combined with in vitro protein expression system and target-specific antibody enables a novel quantitative strategy for such applications. Specifically, a full-length expressed stable isotope-labeled protein generated from a eukaryotic wheat germ system is used as an internal standard in MS to track and quantify not only the protein of interest but also all the PTM within a single protein. The robust in vitro wheat germ system overcomes the laborious, inefficient, and low yield process in protein standard production. Moreover, this MS-based quantification method only requires sub-microgram amounts of protein standard for analysis. When an antibody for the protein of interest is available, it even allows quantification of low-abundance proteins and their PTM. Abnova provides ready-to-use, in vitro wheat germ expression kits and a library of available antibodies covering all the essential protein families to assist you to start and achieve your quantitative needs.


in vitro Wheat Germ Expression System

Contents of Kit:
  • WEPRO1240H
  • SUB-AMIX (S1-S4)
  • SP6 RNA Polymerase
  • RNase Inhibitor
  • NTP Mix
  • 5x Transcription Buffer
  • Creatine Kinase

Monoclonal Antibody



The AB SCIEX TripleTOF™ 5600 System is the first accurate-mass, high-resolution LC/MS/MS system for qualitative analysis that has the speed and sensitivity to deliver quantitation like a high-performance triple quad.

  Compatible Instruments:
  • Thermo LTQ-Orbitrap
  • Waters G2

The Workflow


Publication Reference

FLEXIQuant: a novel tool for the absolute quantification of proteins, and the simultaneous identification and quantification of potentially modified peptides.
Singh S, Springer M, Steen J, Kirschner MW, Steen H. J. Proteome Res. 8(5), 2201–2210 (2009).

For any inquiry, please contact : OEM@abnova.com

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