What is co-transfection and how does it work?

Co-transfection refers to the simultaneous transfection of two separate nucleic acid molecules into a cell, allowing each to carry out its function within the same cell.

Figure 1. Example of co-transfection. A DNA plasmid and siRNA molecule are co-transfected into a single cell.

There are many uses for this transfection application, including:

  • Co-transfection of a marker or selection gene along with another nucleic acid. An example of this application is when a reporter gene (e.g., GFP) is co-transfected with another nucleic acid (e.g., plasmid containing gene of interest). In addition, co-transfection can concurrently deliver both a gene of interest and an antibiotic resistance gene into cells, allowing for selection and generation of a stable cell line.
  • Co-transfection of siRNA and a DNA plasmid encoding the target gene. This allows the efficiency of the intended siRNA knockdown to be tested.
  • Co-transfection of two separate vectors encoding different proteins. This allows protein-protein interactions to be analyzed.
  • Co-transfection of multiple DNA plasmid vectors into packaging cells for the production of viral vectors. Packaging plasmids encode essential viral structures, such as the envelope and capsid. Another plasmid is engineered to contain the gene of interest.
  • Co-transfection of individual vectors for Cas9 nuclease and CRISPR gRNA in gene editing experiments.


Find co-transfection reagents

Selecting the right reagent is essential to ensuring co-transfection efficiency and success. Invitrogen Lipofectamine reagents are proven to be effective for co-transfection experiments.

Lipofectamine 3000 reagent

Lipofectamine 3000 reagent uses advanced lipid nanoparticle technology, enabling exceptional transfection performance. It delivers exceptional transfection efficiency into a wide range of difficult-to-transfect and common cell types.

Explore Lipofectamine 3000

Lipofectamine 2000 reagent

Lipofectamine 2000 reagent is a proprietary formulation that facilitates highly efficient delivery of short interfering RNA (siRNA) or plasmid DNA to mammalian cells.

Explore Lipofectamine 2000

In addition to these Lipofectamine reagents, explore our wide range of other transfection products.


Co-transfection protocol with Lipofectamine 2000 reagent

To see guidelines for ensuring high co-transfection efficiency in RNAi experiments, please visit our protocol for co-transfection of plasmid DNA and RNAi molecules using Lipofectamine 2000 reagent.

View the co-transfection protocol

Visit Transfection Basics to learn more about performing transfection in your lab.

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