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Bicistronic or Internal Ribosome Entry Site (IRES) Element — Efficient co-expression of two genes in a single vector


The IRES element is exactly what's needed for certain experiments when a single-gene vector falls short. IRES enables the coordinated co-expression of two genes with the same vector. For example, you can monitor the delivery of one gene by using a second gene with a fluorescent tag or express a protein of interest and simultaneously biotinylate it with the same vector. An IRES element is especially useful for gene delivery when working with stem and primary cells and when the following tasks are pursued:

  • Monitor gene delivery efficiency
  • In vivo biotinylation
  • Stable transfection


OmicsLink ORF cDNA clones with IRES element



The IRES technology serves a dual-purpose. It allows the coordinated and efficient expression of two genes using the same promoter in a single vector (see figures 1 and 2). Virtually any combination of genes is possible. GeneCopoeia has already developed many constructs.


Combined with OmicsLink expression-ready clones

For a variety of applications, GeneCopoeia has incorporated the IRES element into several mammalian and lentiviral vectors using a wide choice of reporter genes including the following:

  • eGFP
  • mCherry
  • SUMO
  • biotin ligase
  • neomycin
  • luciferase


More than 20,000 human and 15,000 mouse genes are available in CMV promoter driven bicistronic (IRES) expression vectors.

Choice of co-expressing any reporter gene with IRES element



  • Minimal effect on biological activities of target proteins when co-expressed with reporter/ assaying genes.
  • Efficient co-transfection due to coordinated co-expression of two genes from a single expression vector.






OmicsLink ORF cDNA clones with IRES element





Figure1. OmicsLink™ ORF cDNA expression clones with IRES element in mammalian and lentiviral expression vector systems.

Applications and Data


  • Monitor gene delivery efficiency by co-expressing proteins with reporter genes including eGFP, mCherry or Luciferase.
  • In vivo biotinylation of expressed proteins with AviTag by co-expressing with biotin ligase.
  • Establish stable transfected cell lines for efficient selection by co-expressing with selection marker genes like Neomycin.


Rigorous quality control and assurance process

All ORF cDNA clones in OmicsLink collection were generated from sequence validated full-length cDNA clones or high-quality human tissue cDNA libraries to construct expression-ready clones.

Once the clone is constructed, GeneCopoeia follows additional quality control processes to ensure the right clone is delivered.

  • All ORF cDNA are fully sequenced.
  • PCR amplification and size validation
  • Enzyme digestion check of the integrity of whole plasmid

How it works

Schematic of protein expression with IRES technology

Specific biotinylation of AviTag eGFP by E. coli biotin ligase in 293 cells

Figure 2. Specific biotinylation of AviTag eGFP by E. coli biotin ligase in 293 cells


List of expression vectors with IRES technology

Vector Promoter Host Cell Selection Marker Tag Protease Site
pReceiver-Lv165 EF1a Stem/primary/others* N/A IRES2-eGFP N/A
pReceiver-Lv166 EF1a Stem/primary/others* N/A IRES2-mcherry N/A
pReceiver-Lv201 CMV Stem/primary/others* Puromycin SV40-eGFP-IRES-puromycin N/A
pReceiver-Lv202 CMV Stem/primary/others* Puromycin C-Myc-SV40-eGFP-IRES-puromycin N/A
pReceiver-Lv203 CMV Stem/primary/others* Puromycin C-Flag-SV40-eGFP-IRES-puromycin N/A
pReceiver-Lv204 CMV Stem/primary/others* Puromycin C-Myc-SV40-mCherry-IRES-puromycin N/A
pReceiver-Lv205 CMV Stem/primary/others* Puromycin IRES2-eGFP-IRES-puromycin N/A
pReceiver-Lv206 CMV Stem/primary/others* Puromycin SV40-mCherry-IRES-puromycin N/A
pReceiver-Lv207 CMV Stem/primary/others* Hygromycin SV40-eGFP-IRES-hygromycin N/A
pReceiver-Lv211 CMV Stem/primary/others* Hygromycin C-Halotag-IRES-hygromycin N/A
pReceiver-Lv213 CMV Stem/primary/others* Puromycin IRES2-mCherry-IRES-puromycin N/A
pReceiver-Lv214 CMV Stem/primary/others* N/A IRES2-mCherry N/A
pReceiver-Lv215 CMV Stem/primary/others* N/A IRES2-eGFP N/A
pReceiver-Lv216 CMV Stem/primary/others* Puromycin C-Flag-SV40-mCherry-IRES-puromycin N/A
pReceiver-Lv217 CMV Stem/primary/others* Puromycin SV40-hLUC-IRES-puromycin N/A
pReceiver-Lv220 CMV Stem/primary/others* Hygromycin IRES2-Hygromycin N/A
pReceiver-Lv224 EF1a Stem/primary/others* Puromycin IRES2-mcherry-IRES-puromycin N/A
pReceiver-Lv225 EF1a Stem/primary/others* Puromycin IRES2-eGFP-IRES-puromycin N/A
pReceiver-Lv228 PGK Stem/primary/others* N/A IRES2-eGFP N/A
pReceiver-Lv229 PGK Stem/primary/others* N/A IRES2-mcherry N/A
pReceiver-Lv230 PGK Stem/primary/others* Puromycin IRES2-mcherry-IRES-puromycin N/A
pReceiver-Lv231 PGK Stem/primary/others* Puromycin IRES2-eGFP-IRES-puromycin N/A
pReceiver-M45 CMV Mammalian Neomycin C-3xHA+IRES-eGFP N/A
pReceiver-M46 CMV Mammalian Neomycin C-Flag+IRES-eGFP N/A
pReceiver-M48 CMV Mammalian Neomycin N-Avi+IRES-Biotin ligase N/A
pReceiver-M51 CMV Mammalian Neomycin C-His+IRES-eGFP N/A
pReceiver-M61 CMV Mammalian Neomycin IRES2-eGFP N/A
pReceiver-M72 CMV Mammalian Neomycin C-Myc+IRES2-eGFP N/A

Learn more about expression-ready ORF cDNA clone collection available in bacterial, mammalian, insect, yeast and wheat germ cell free systems with more than 50 fusion tags.



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