Protein production

Recombinant protein production service

Icosagen provides recombinant protein production services using proprietary CHO-based QMCF Technology in serum-free conditions. Customer benefits are a short production time and cost-efficiency.

We offer two options for protein production:

  1. Enhanced transient expression of recombinant proteins using high copy number transient pQMCF-T expression vectors. This option is fast, and a good fit for a small-scale pilot study to test the best expression conditions for your protein of interest.
  2. Production using stable episomal production pools for large-scale production using pQMCF expression vectors that are stably maintained in proliferating CHO cells. This option is scalable and suitable for the cost effective production in up to 40 liter scale, and to produce protein of interest in up to gram-scale. 

Transient production of recombinant proteins includes:

  • cDNA optimization and cloning into transient pQMCF-T expression vector
  • Chemical transfection of QMCF/CHOEBNALT85 cell line and expression/secretion control 48 hours after transfection
  • Optional culture expansion (up to 2.5 folds) and recombinant protein production
  • Harvesting and protein purification
  • Product analysis and characterization 
  • Weekly updates, and detailed reports


Stable production including selection and cell bank generation:

  • cDNA optimization and cloning into pQMCF expression vector
  • Electroporation of QMCF/CHOEBNALT85 cell line and expression/secretion control 48 hours after transfection
  • G418 selection and generation of production cell bank (stable episomal pool)
  • Culture expansion to the final production volume and recombinant protein production 
  • Harvesting and protein purification
  • Product analysis and characterization 
  • Weekly updates, and detailed reports



Process DescriptionDeliverables
cDNA optimization and cloning into pQMCF expression vector
Sequence data, construction information
Transfection and antibiotic selection (in the case of  stable production) for enrichment of protein production cell population 
Expression/secretion data at 48 hours after transfection
Generation of production cell bank
(not applicable in transient production format)
At least 2 vials of the cell pool expressing protein of interest
Recombinant protein production 
Protein-containing cell culture medium.  Production analysis data (WB, ELISA, Coomassie-stained SDS-PAGE, Octet K2)
Purification optimization and purification
Purification protocol, and purified protein (>95% purity; less than 2% aggregates)
Product characterization
Project report including QC data (WB, ELISA, Coomassie-stained SDS-PAGE, analytical SEC, binding and kinetics analysis by Octet K2)


Produced recombinant proteins are suitable for various types of pre-clinical investigations: drug discovery, antibody generation, structural biology, functional characterization, development of analytical and diagnostic tools.