The evolution of transient protein expression with Expi platforms

At the research scale, transient protein expression platforms offer protein production labs many advantages over a stable system. However, this wasn’t always the case. Stable production used to be the only way to produce meaningful amounts of protein in a relatively short time period until in 2012 when Gibco launched Expi293 Expression System.

At the platform’s debut, the Expi293 transient expression platform offered up to 6x higher yield than previous transient systems and enabled protein harvest in as little as one week, which was weeks if not months faster than that achievable via stable development. Thermo Fisher Scientific has since continued to innovate upon the “Expi” platforms and launched ExpiCHO Expression System in 2015 and ExpiSf Expression System in 2018. For researchers and facilities needing to rapidly produce high amounts of protein, the Expi protein expression systems offer integrated solutions with yield, speed, and cost benefits.

Benefits of rapid, high-yield transient protein production

In addition to the obvious yield benefits offered by Expi platforms, labs can help minimize the burden on their staff by reducing hands-on-time needed for protein production, freeing up researchers to perform more experiments and analysis.


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Stable cell line production can take almost a month; with Expi systems you can obtain sufficient yield to transiently express protein in as few as 5 days.


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For researchers who need as much protein as possible, we've developed protocols that maximize yields without adding a significant time investment.


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Since Expi systems offer high-yield and rapid expression, scientists can save on their cost/mg of protein (based on decreased plastics use, reduced staff time, and reduced DNA).

Transient protein expression systems by host type

Discover the benefits of our transient protein expression systems by host type. 


ExpiCHO Expression Kit

  • Host type: Mammalian
  • Cell line: High-yield ExpiCHO-S cells
  • Days: 7-14 days
  • Protein yield: Up to 3g/L
  • Cost*: $0.10/mg

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Expi293 Expression System

  • Host type: Mammalian
  • Cell line: High-yield Expi293F cells
  • Days: 5-7 days
  • Protein yield: Up to 1g/L
  • Cost*: $0.32/mg

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ExpiSf Expression System

  • Host type: Insect
  • Cell line: High-yield ExpiSf9 cells
  • Days: 6-10 days
  • Protein yield: Up to 900mg/L
  • Cost*: $1.10/mg

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*Note “Cost” above refers to a typical cost for a protein expression project in US dollars.

Transient protein expression systems by application

Not sure what system is right for you? Expand the links below to discover how transient protein expression is utilized in each application.

The ExpiSf Expression System accelerates vaccine development with the first chemically defined insect culture medium and integrated components designed to enable cost-effective and high-yield production of proteins and viral particles with consistent performance, run-after-run using a fast, streamlined, and highly-scalable workflow. With the simplicity, scalability, and cost-effectiveness of ExpiSf, you can get closer to your next vaccine breakthrough faster.

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Insect cells help enable the expression of intracellular proteins and multi-protein complexes. The ExpiSf Expression System is a suitable platform for high-titer production of these macromolecules with the added benefit of a faster workflow that helps enable you to obtain high-titer recombinant baculovirus in one simple step and going from transfection to product harvest in 6-10 days.

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The Expi293 Expression System is designed with human HEK293 suspension cells, optimized medium, and transfection reagent that help enable native folding and high protein yields required for structural biology applications. Whether your structural biology studies rely on X-ray crystallography or NMR the Expi293 Expression System and tools for Structural Biology provide a complete, simple, and cost-effective system to help your work.

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While insect cells perform most of the post-translational modifications that occurs in mammalian cells, N-glycosylation in insect cells results in only simple glycan moieties as opposed to complex glycans that occur in mammalian cells, such as those in the Expi293 Expression System. For structural analysis where simple protein glycosylation is favorable, ExpiSf Expression System can be an alternative, low-cost platform for these applications.

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The Expi293 Expression System provides a platform for the fast and high-yield production of reagent proteins with human protein glycan patterns.

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The ExpiSf Expression System offers a rapid and inexpensive path for the transient production of protein intended for use as a reagent protein.

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The Expi293 Expression System is a fast and high-yield expression platform for the development of protein drug targets and antibody production. Because of its human glycan patterns, the Expi293 System is a superior choice for producing receptor proteins, kinases, GPCRs, and other target proteins of interest for potential drug therapies.

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Reducing cost and shortening timelines are among the top needs in biologics development. The ExpiCHO platform comprises a family of integrated components that helps streamline biologics development by providing an end-to-end, integrated, and high-productivity solution. This unified approach helps minimize key quality risks during development by enabling the use of the same cell line from transient to stable production while streamlining process development by utilizing integrated reagents for unmatched performance.

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The Expi293 Expression System provides a platform for the fast and high-yield production of reagent proteins with human protein glycan patterns.

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The ExpiSf Insect Protein Expression System provides a rapid and inexpensive path to transient protein production for use as a reagent protein.

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The Expi293 Transient Protein Expression System offers a kit for methionine labeling of proteins for use in X-ray crystallography and other applications where protein labeling and analysis is desired.

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The Expi293 Protein Expression System offers methionine-deficient expression medium and transfection kit to help enable efficient labeling of high-yield proteins for use in structural analysis. Custom media with selective removal of amino acids is available for more complex labelling needs.

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For analyzing protein interactions and activity, the Expi293 Expression System provides human-like proteins designed to help you see how a native protein would interact with your therapeutic candidate. After producing your protein, be sure to use our activity assays to help determine your therapeutics effectiveness.

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In protein interaction and activity analyses, the Expi293 Expression System provides human-like proteins for in vitro assessment of native protein interactions with therapeutic candidates. After protein production, our activity assays determine effectiveness of your therapeutic agent.

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When preparing for biologics development, it is important to start with a development platform that keeps your production plans in mind. Using the ExpiCHO Expression System you can seamlessly transition from research to production to save time and effort when you need to scale as soon as possible.

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leaf icon Less waste

When minimizing waste in your lab, every little bit helps. The 1 L Gibco bottle uses 38% less source material (32% less for the 0.5 L bottle) than comparable media bottles on the market today. This reduces the consumption of non-renewable resources helping shrink your footprint.

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Protein Expression Publication Hub

Protein Expression publication hub

The Protein Expression Publication Hub features a curated list of publications that offers an in-depth look into how scientists like you advance their research with Expi protein expression systems.

Our systems are optimized to harness the power of transient expression with the goal of delivering high-yield, consistent proteins for a diverse array of downstream applications. Search now

For Research Use Only. Not for use in diagnostic procedures.