There are many options in selecting a viral delivery system matched to your specific needs. Life Technologies™ offers a variety of viral vector systems for delivering nucleic acids into mammalian and insect cells for protein expression and RNAi studies.

Expression in mammalian cells

ViraPower™ Expression Systems from Life Technologies™ use replication-incompetent viral particles to ensure safe and highly-efficient delivery of expression constructs for high-level constitutive or inducible expression in any mammalian cell type. A number of vectors available for use with the ViraPower™ systems offer various options for
cloning method (TOPO® or Gateway® cloning, or GeneArt® genetic assembly) and promoter choice (constitutive or inducible), allowing the optimization of the experiment for each cell line or animal model.

  • ViraPower™ Lentiviral Expression System allows stable protein expression in dividing and non-dividing cells (e.g., stem cells, primary neuronal cells), and are ideal for analysis of long-term gene expression and functional analysis studies.
  • ViraPower™ HiPerform™ Lentiviral Expression System improves on the existing lentiviral systems by including the woodchuck posttranscriptional regulatory element (WPRE) and the central polypurine tract (cPPT) sequence from the HIV-1 integrase gene in the viral vectors for increased expression and increased lentiviral integration into the host genome, respectively. The ViraPower™ HiPerform™ kits have two versions: kits for high accuracy titer, allowing for precise control of copy number per cell, or kits for fast titering, which are ideal for high throughput screening studies.
  • ViraPower™ Lentiviral T-REx™ System combines the ViraPower™ HiPerform™ Lentiviral, T-REx™, and Gateway® technologies to facilitate easy recombinationbased cloning and lentiviral-based, regulated (Tetracycline-inducible), high-level expression of a target gene in dividing and non-dividing mammalian cells. This system is ideal expressing toxic proteins, because the inducible promoter allows the control of the timing of gene expression.
  • ViraPower™ Adenoviral Expression System is ideal for protein production, and allows high-level transient gene expression in dividing and non-dividing mammalian cells from the CMV or another promoter of choice. The ViraPower™ Adenoviral System uses Gateway® Technology for fast, easy, and accurate cloning of the gene of interest.

Learn more about ViraPower™expression systems

Viral system Transient expression Stable expression
Cell state Dividing cells Non-dividing cells Dividing cells Neuronal cells Growth - arrested cells Contact - inhibited cells

Expression in insect cells

Expression in insect cells offers significant advantages, including high expression levels, ease of scale-up, and simplified cell growth that is readily adapted to high-density suspension culture. Furthermore, because many of the posttranslational modification pathways present in mammalian systems are also utilized in insect cells, proteins produced in insect cells are antigenically, immunogenically, and functionally similar to native mammalian proteins. Life Technologies™ offers powerful and versatile baculovirus expression systems for high-level, recombinant protein expression in insect cells.

  • BaculoDirect™ Baculovirus Expression System is a fast and easy method for generating recombinant baculovirus using recombinational Gateway® cloning. Baculovirus expression systems typically require bacterial transformation and isolation of a large bacmid or co-transfection of a transfer vector and linear baculovirus DNA into insect cells. The BaculoDirect™system eliminates these timeconsuming steps, allowing the isolation of purified virus within one week. The reduction of hand-on time for baculovirus generation makes the BaculoDirect™ system ideal for high-throughput expression.
  • Bac-to-Bac® Baculovirus Expression System uses a unique bacmid shuttle vector that recombines by site-specific transposition to generate an expression bacmid in bacterial cells. The bacmid is then transfected into insect cells for the production of recombinant baculovirus particles. With easy blue/white screening of recombinant colonies, the Bac-to-Bac® Baculovirus Expression System is designed for fast, small scale production of recombinant baculovirus.
  • Bac-to-Bac® HBM Baculovirus Expression System enables secreted protein expression via the honeybee melittin (HBM) secretion signal, which is ideal for proteins and glycoproteins that require a secretion signal to be glycosylated. In contrast to glycoproteins secreted from mammalian cells, glycoproteins secreted from baculovirus can be easily de-glycosylated in vitro, which is essential for crystallizing the proteins.
  • Bac-N-Blue™ Baculovirus Expression System is the classic and trusted expression system for high-level recombinant protein production in insect cells. Recombinant viral DNA is generated by co-transfection of a transfer vector containing the gene of interest and the linear baculovirus DNA into insect cells. Recombinant baculovirus is isolated using a blue/white plaque visualization method, and then amplified in insect cells to generate a high-titer viral stock to initiate expression studies.

Lean more about baculoviral expression systems

System Host Secretion signal Fusion partner position Fusion partner purif. Fusion partner epitope Promoter Expression / inducer Advantage
BaculoDirect™ Sf9, Sf21, or High Five™   N-term
Polyhedrin Infection Fast and easy; ideal for high-throughput
Bac-to-Bac® or Bac-to-Bac® HBM Sf9, Sf21, or High Five™ Honeybee
6xHis pFastBacHT
Polyhedrin or P10 Infection
Rapid baculovirus production; easy blue / white selection
Bac-N-Blue™ Sf9, Sf21, or High Five™ Honeybee
C-term 6xHis Xpress™
Polyhedrin Infection High-level recombinant protein production
DES® S2 cells BIP C-term 6xHis V5 MT or Ac5 CuSO4 or constitutive Constitutive or inducible expression; extremely high integration