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Quantitative Recombinant Protein Standards – qRePS™

Amino acid overlap of a single qRePS with respective target protein with enzymatically digested proteotypic peptides. Such design ensures accurate and precise multi-peptide quantification.

Quantitative Recombinant Protein Standards (qRePS™), the solution to your quantitative proteomics needs. Our Lys and Arg 13C and 15N labeled recombinant human protein fragments are designed to serve as internal standards in MS-based quantitative proteomics experiments. qRePS are cleavable standards ensuring accurate and precise multi-peptide quantification while being compatible with standard workflows.

Our qRePS are delivered as multiplex panels specifically designed for analysis of raw blood plasma in prealiquoted 96-well plates and easy-to-use vacuum dried format. Each qRePS within our panels has been titrated to represent the respective target protein amount requiring only an equivalent of one microliter of raw blood plasma to be added.

qRePS™ Production

qRePS are individually produced in an auxotrophic E. coli and minimal media. During the production process we employ a variety of steps and quality control measures ensuring the highest grade for our products with focus on purity and absolute determination of quantity for each individual qRePS. Each standard consists of hexahistidine (His6) sequence followed by albumin binding protein derived from streptococcal protein G. This design ensures the product reliability and longitudinal stability.

Recombinant production and purification of all individual qRePS
All individually produced qRePS undergo thorough quality control scrutiny ensuring the highest grade of each product

Designed for blood plasma analysis

All individual qRePS are titrated to concentration levels of blood plasma serving as single point calibration standards during absolute quantification in an MS-based proteomics experiment. They are pooled into panels for multiplex protein quantification and various applications and research needs though, maintaining the performance and focus on the quantification precision and accuracy. All our multiplex panels are provided in 96-well plates and dry format ensuring remarkable stability and robustness.

The single qRePS are pooled into panels to represent expected blood plasma concentration levels of target proteins, accurately aliquoted into 96-well plates and vacuum for the best quantitative performance


This easy-to-use configuration requires only an equivalent of 1 µL of raw blood plasma to be added onto our dried qRePS panel. When blood plasma is added, qRePS are immediately dissolved establishing an equilibrium between the endogenous proteins and all individual qRePS which enables for unbiased and robust absolute quantification. The qRePS technology is suitable for majority of standard sample preparation workflows and fully automated pipelines. Besides the trypsin being the enzyme of choice for majority of experiments, qRePS can be utilized with variety of other enzymes that suit your research needs.

Sample preparation outline where qRePS and blood plasma are mixed as the first step of MS-based proteomics workflow. Blood plasma proteins are subsequently enzymatically digested and absolutely quantified using the ratio of heavy qRePS and endogenous peptides.


  • Multiplex mixture of internal standards for MS-based quantitative proteomics
  • Accurate determination of plasma proteins
  • Metabolically labeled standards for maximum sensitivity
  • Designed for easy handling
  • Quality guaranteed
  • Thousands of experimentally verified peptides for your quantification
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