Mammalian Protein Expression Service

Recombinant proteins are proteins produced from transfecting artificially-made DNA into a host cell. Mammalian recombinant proteins derived from mammalian cells are commonly used in pharmaceuticals to generate therapeutic protein, drug-delivery systems, or to investigate cellular systems. ProMab Biotechnologies, Inc. offers recombinant protein expression service in mammalian cells. Our high-level mammalian expression system produces human cell line-derived proteins with full glycosylation, allows you to scale up to 50 liters, and request tag removal.

Recombinant protein production generally begins with cloning of the desired gene into a vector. Following sequence confirmation, we conduct a small and mid-scale transfection to validate the desired protein and test its expression levels. We then conduct a large-scale transfection of the recombinant vector into CHO or HEK293 cells for protein expression, purification, and optimization.

Similar to the benefits of E.coli expression, mammalian expression offers high-level expression of the recombinant protein, fast turn-around time, and we can remove tags as requested. However, the main advantage is that mammalian expression can produce mammalian proteins with all the post-translational modifications. 

Below is the breakdown for the standard mammalian expression service by phase. We also offer protein expression services including E. coli Expression and Baculovirus Expression. For additional inquiries on any of our protein expression services, please contact us and we would be glad to answer any of your questions.  


Breakdown of Standard Service by Phase 

Phase I

Phase II

Phase III

  • Cloning of your gene of interest into vector with his-tag or IgG-Fc tag (human or murine)

  • Sequence confirmation of insert

  • Small scale (10 mL) transfection to test the expression level; and subsequent optimization if necessary

  • Mid-scale transfection (50mL) and purification

  • SDS-page validation

  • Large scale transfection (1L) of recombinant vector into HEK293 or CHO cells, and protein expression, evaluation and optimization

  • Protein purification from 500 mL of HEK293 or CHO cell culture using Ni-NTA or Protein G affinity purification columns (tag cleavage provided at additional cost).

$2,000 due at the beginning of phase
Estimated time: 3-4 weeks

$2,500 due at the beginning of phase.
Estimated time: 2-3 weeks

$3,500 due at the beginning of phase
Estimated time: 4 weeks

Yield ranges from 200 µg-25 mg/L of culture with average yield of 3mg/L
Total time = 9-10 weeks ±
Total cost= $8,000

Deliverables: 5 µg of transfer vector, protein, and documentation.


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Stable Cell Line Services

Using our Mammalian Expression Platform, ProMab also offers a proprietary stable cell line development service for research and biopharma applications.
Stably-transfected cell lines are used for many drug discovery assays such as screening and validation. Compared to traditional antibody production methods, utilizing a stable cell line overcomes many production issues and inconsistencies that come with hybridoma production or standard transient expression. For cost-effective large scale production, a stable cell line is the way to express your gene of interest. Furthermore, a stable cell line allows for persistent and reproducible expression for your gene of interest over many passages.
Our mammalian expression and stable cell line platform provides a one-stop-shop for expert-level services to your research and development. To learn more about our services, or to request a quote, please click below.