What expression systems does Biointron use for mammalian protein expression?

Biointron utilizes mammalian cell systems, such as CHO-K1/HEK293, for protein expression, ensuring high yield and quality.

What materials do I need to start a recombinant protein expression project in mammalian cells?

Clients need to provide the protein sequence.

What is the standard turnaround time for recombinant protein production in mammalian systems?

Most recombinant protein expression projects in CHO-K1 or HEK293 cells are completed within 3-4 weeks, depending on the protein’s complexity, expression level, and purification requirements.

What quality control measures are implemented during recombinant protein production in mammalian cells?

Biointron provides SDS-PAGE, SEC-HPLC, and endotoxin results by default. Additional QC measures can be included by request.

What deliverables will I receive upon project completion?

Clients receive purified protein and expression plasmids containing your gene of interest, along with a full CoA report.

Recombinant Protein Expression Services in Mammalian Cells

Choice of Expression Platform
High-Quality Proteins for Diverse Applications
Scalable and Efficient Workflows

Home > Recombinant Protein Expression > Recombinant Protein Expression in Mammalian Cells & E.coli

Have your recombinant proteins expressed in mammalian or bacterial cell systems in 3-4 weeks.

Biointron provides mammalian and bacterial recombinant protein expression services tailored for the scalable production of complex, functional proteins. The platform is optimized for expressing enzymes, secreted proteins, soluble proteins, and more. We support clients developing therapeutic antibodies, diagnostic assays, and research-grade proteins.

You can have your proteins expressed in either CHO-K1 and HEK293 cells for mammalian systems, or E. coli for bacterial expression. The mammalian platforms are suitable for proteins requiring glycosylation, disulfide bond formation, or other eukaryotic modifications, while E. coli is appropriate for non-glycosylated proteins, cytoplasmic enzymes, and proteins amenable to refolding or fusion tag-based purification. This flexibility allows clients to match protein characteristics with the most cost-effective and scalable system.

Recombinant Protein Expression in Mammalian Cells & E.coli Overview

Key Advantages of Biointron’s Protein Expression Services

Choice of Expression Platform

CHO-K1 and HEK293 systems for proteins requiring proper folding, glycosylation, and other post-translational modifications.
E. coli expression for rapid, high-yield production of non-glycosylated proteins, cytoplasmic enzymes, and fusion tag constructs.
Flexibility to match protein characteristics with the most suitable expression host.

High-Quality Proteins for Diverse Applications

Production of enzymes, secreted proteins, soluble proteins, and antibody fragments for research and diagnostic use.
Proteins validated through SDS-PAGE, SEC-HPLC, and endotoxin testing (<1 EU/mg) to ensure purity and integrity.
Suitable for functional assays, antibody screening, structural biology, and preclinical research support.

Scalable and Efficient Workflows

Pilot-scale production (100 mL) to test feasibility before scaling up to 1–10 L.
Codon optimization, transient expression, and affinity purification included as standard workflow steps.
Typical project turnaround of 3–4 weeks, with plasmids, purified protein, and a full certificate of analysis provided as deliverables.

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Mammalian Expression for Proper Folding and Modifications

Mammalian cell systems enable proteins to undergo folding, glycosylation, disulfide bond formation, and other post-translational modifications essential for maintaining biological activity. This makes CHO-K1 and HEK293 expression the preferred choice for functional assays, antibody screening, and structural studies. Biointron validates each production run using SDS-PAGE, SEC-HPLC, and endotoxin analysis to confirm purity and quality. With flexible options from pilot expression to multi-liter scale production, our mammalian expression services deliver reproducible proteins that meet the needs of both academic and industrial research.

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E. coli Expression for Rapid and Scalable Production

For proteins that do not require post-translational modifications, E. coli expression offers a fast and efficient alternative. This system is particularly well suited for producing proteins for biochemical assays, antibody libraries, and applications where high yield is essential. At Biointron, bacterial expression workflows include gene design, vector construction, protein induction, purification by chromatography, and rigorous quality control. By offering both mammalian and bacterial platforms, we provide researchers with the flexibility to choose the most suitable system for their protein’s characteristics and project goals.

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Step-by-Step Workflow for Protein Expression

Gene Synthesis

Plasmid construction and preparation

Transient expression

Affinity purification

Stringent quality control

Fast delivery

Expression in Mammalian Cells
Service Details

Service Step	Service Description	Timeline	Deliverables
Gene synthesis	Codon optimization and gene synthesis Subcloning into an expression vector Plasmid amplification and preparation	2-3 weeks	Expression plasmid contain GOI Purified Recombinant protein (SDS-PAGE and SEC-HPLC detection, endotoxin level <1EU/mg) COA report
100ml Pilot study	Transfection of mammalian cells 100ml pilot protein expression QC analysis	2-3 weeks
Scale up production(1L-10L)	Large scale protein expression Affinity purification QC analysis	3-4 weeks	Purified Recombinant protein (SDS-PAGE and SEC-HPLC detection, endotoxin level <1EU/mg)

Gene synthesis
Timeline

2-3 weeks

Description
- Codon optimization and gene synthesis
- Subcloning into an expression vector
- Plasmid amplification and preparation
Deliverables
- Expression plasmid contain GOI
- Purified Recombinant protein (SDS-PAGE and SEC-HPLC detection, endotoxin level <1EU/mg)
- COA report
100ml Pilot study
Timeline

2-3 weeks

Description
- Transfection of mammalian cells
- 100ml pilot protein expression
- QC analysis
Deliverables
- Expression plasmid contain GOI
- Purified Recombinant protein (SDS-PAGE and SEC-HPLC detection, endotoxin level <1EU/mg)
- COA report
Scale up production(1L-10L)
Timeline

3-4 weeks

Description
- Large scale protein expression
- Affinity purification
- QC analysis
Deliverables
- Purified Recombinant protein (SDS-PAGE and SEC-HPLC detection, endotoxin level <1EU/mg)

Case Study

Case 1: PD-L1 (Fc tag), Extracellular domain (Phe19-Thr239) expressed in CHO

R: Reducing condition;

N-R: Non-reducing condition;

M: Marker

Case 2: CD137 (His tag), Extracellular domain (Leu24-Gln186) expressed in HEK293

R: reducing condition;
M: Marker

Human CD137L/mFC; Human CD137/ His;

Recombinant Human CD137/His is captured on Protein A chip, can bind to Human CD137L/mFc.

Log Human CD137, His tag EC50=4ng/ml

CD137 is immobilized at 2µg/mL (100 µL/well), it can bind to Utomilumab. The concentration for 50% of maximal effect(EC50) of is 4 ng/ml.

Log Human CD137, His tag EC50=20ng/ml

CD137 is immobilized at 2µg/mL (100 µL/well), it can bind to Human CD137L. The concentration for 50% of maximal effect(EC50) of is 20 ng/ml.

“We tailor our services according to the client’s needs – we offer the use of either CHOK1 or HEK293 cells for recombinant protein expression. Every successful expression is a step closer to redefining the possibilities in biotechnology and, ultimately, in improving lives.”