Protein Expression Description

• E coli system
  Expressing protein in E coli cells is the most convenient, fastest and most cost-effective way to obtain a fair amount of protein. Approximately 60-70% of human proteins can be expressed in E coli and be functionally active. However, E coli cells lack most modification enzymes and modifications, such as phosphorylation, glycosylation and acetylation. Catalyzation by these enzymes is essential for certain types of proteins, including cytokines, nuclear hormone receptors, protein kinases and other regulatory proteins. The turn-around time is 1-2 weeks.


• Baculovirus system
  Expressing protein in a baculovirus system is the primary choice if post-translational modification is essential for the activity of the protein of interest. More than 95% of human proteins can be expressed in baculovirus and function properly. In general, three different host cell lines are currently used, including Sf9, Sf21 and HighFive cells. The turn around time is 3-6 weeks.


• Mammalian system
  The mammalian system has certain advantages for those proteins with solubility and post-translational modification issues, as well as those to be used in cell function studies. In addition, because so many mammalian cell lines are available, scientists have the option to study specific gene function in a specific cell line. But the major disadvantage is the long turn-around time and higher cost. We provide protein services expressed in a variety of mammalian cells (HeLa, HEK293, CHO, NIH3T3, SH-SY5Y, MCF7, MDA231, MDA468, etc). Either transient transfection or development of stable cell lines is achievable for most mammalian cell lines. The turn-around time is 4-12 weeks.

To Order Protein Expression

Please click on "Request Quote" link above. Please include the following information in your email:

1. Which expression system wanted (bacterial, baculovirus or mammalian)
2. Which protein (protein name, accession number)
3. Which tag is preferred (6His, Flag, GST, MBP, Biotin etc)
4. Amount of purified protein required (from mg to gram level)
5. Purity of the protein requested (80%, 90% or over 95% homogeneity)
6. Other special requirement (such as endotoxin free or specific buffer condition)

We will evaluate your project and get back to you with quote and project duration.

A standard validation method (protein analysis by SDS PAGE and/or Western blot) is included in our service.