Mammalian Protein Expression Service

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Recombinant Protein Expression Service: Protein Expression in Bacterial and mammalian cell system

Tip: How to detect small peptides clearly and sensitively by Western blotting or SDS-PAGE?

LifeTein® offers protein expression in E.coli. and mammalian cell systems. Protein expression in bacterial cells is a fast and economical way for high levels of recombinant proteins.

LifeTein’s mammalian protein expression service provides flexible and rapid production of human, and other mammalian proteins and recombinant monoclonal antibodies. Mammalian expression systems generate recombinant proteins with unique advantages of correct folding, proper post-translational modifications, and optimal structure or native epitope antigenicity.

In combination with the proprietary codon optimization, gene synthesis, and plasmid preparation, our integrated mammalian expression systems, as well as US-New Jersey based lab facility, are capable of maximizing protein productivity with speedy delivery.

LifeTein provides the service from the virtual sequence to purified protein in as little as four weeks. Protein production is supplied at flexible scales and formats, including from 100 ml assay scale up to 20 liters of production in serum-free and suspension culture. You will receive recombinant protein and antibody products that meet your particular specifications and expectations.

LifeTein provides hybridoma sequencing or antibody sequencing for the cDNA encoding the variable domains of heavy (VH) and light (VL) chains of your monoclonal antibody from different species. The engineered antibody genes are constructed into our mammalian cell expression vector for both transient and/or stable cell line antibody production.

Order your Protein Service at a competitive price! Email us at for a quote.

Protein Expression Service and Crystallization

Protein Expression in E.coli It is easy. Your local access to the plasmid preparation, mammalian protein expression facility in New Jersey, USA. Just email us a gene sequence or plasmids in any form. We will have the gene designed, optimized, synthesized, and cloned. Or send us the protein sequence and we will send you milligrams of proteins. Proteins are shipped on dry ice.
Protein Purification It is flexible. Your choice of getting synthetic genes, plasmids, peptides, or proteins. If the 6His tag does not give us an efficient expression, we will change the 6His tag to GST for free.
Protein Ligand Binding It is economical. We offer package prices from gene synthesis, plasmid preparation, cloning, and protein expression to antibody production.
Protein Crystals It is productive. An optimized refolding methodology is available to solve the protein solubility issues. Enhanced expression vectors are used to increase the protein expression scale and bioactivity.
Protein Structure It is large. Need more genes, plasmids, peptides, or proteins? We can scale up the gene synthesis, plasmid preparation, peptide production, or protein expression to hundreds of liters or gram levels.


Gene Synthesis: Subclone to your vector at a competitive price. By default, we clone genes into our pUC19 or pUC57 vector for free, subcloning will add an additional two days.
  • Free codon optimization: Optimized genes have higher protein expression in their corresponding hosts.
  • Fast turnaround time. 1-2 weeks for <1.5 kb genes. 2-3 weeks for genes of 1.5 kb to 5 kb.
  • Advanced synthetic technology for complex genes with repetitive, AT or GC-rich DNA.
Bacterial Expression System: Different optimized conditions are used for clones to find the optimum soluble expression condition with our system. The pET expression system provides a high level of protein production.
  • E. coli system for soluble protein with high stability
  • Classic poly-Histidine tag for proteins of interest
  • High-affinity FLAG or GST tag for protein with very low expression level
Mammalian transient protein expression service
  • Mammalian transient protein expression system to meet the demand for economic and large amounts of eukaryotic proteins in their native conformation
  • Different purification tags on customers' request
  • Cell culture in 293 or CHO suspension culture cell lines for optimum expression

Frequently Asked Questions: Protein, antibody expression, and purification

1. How long does a mammalian transient protein expression project usually take?

Starting with the mammalian expression plasmid, our service can be completed in 5-9 weeks.

2. What advantages does a mammalian transient protein expression system provide?

Mammalian expression systems can be used when a target protein with posttranslational modifications is needed for functional and structural studies. Peptide synthesis is usually for difficult proteins that are not feasible within any protein expression system. In addition, the eukaryotic system is completely safe. You just need to provide the protein sequence, antibody sequence or hybridoma cells, we will provide the proteins or antibodies.

3. What if my gene does not express well?

We have different expression strains and leader sequences for optimizing expression. Options of refolding methods and tags are used for the best conditions.

LifeTein Refolding Technology

Recombinant proteins accumulated intracellularly form inclusion bodies, or insoluble aggregates of misfolded protein lacking biological activity. Proteins have to fold in a correct conformation. In this way, specific sites of the right size, shape, and polarity are created for their ligands or receptors. Conventional methods for refolding insoluble recombinant proteins include slow dialysis, ion exchange, gel filtration, or dilution into a buffer of near neutral pH.

LifeTein's refolding technology is based on a simple and historically successful protocol. This method reduces protein waste and minimizes unnecessary analysis. The simplified protocol provides reliable, high-yield, and high concentration of refolded proteins.

Quotations: Email your protein service inquiry to We will send you a formal quote within 24 hours.